title: Horizontal RecyclerView inside NestedScrollView, can't scroll vertically
body: <p>I tried every combination of this, some people said it's a bug but I think it's something small I'm missing. With the follwing XML, I can't scroll at all, only the horizontal scroll works.</p>
  
  <p>I have a side-scroll RecyclerView which I can drag left and right, but the page has more I items than can fit, hence the ScrollView.</p>
  
  <p>At first I was aiming for a collapsable toolbar, but when I add CoordinatorLayout, the activity is just blank.</p>
  
  <p>My XML:</p>
  
  <pre><code>&lt;android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:nestedScrollingEnabled="true"
      app:layout_constraintTop_toBottomOf="@+id/scrollv"
      tools:context="com.wearecatchapp.blueandwhite.catchapp_droid.EventDetailActivity"&gt;
  
      &lt;android.support.v7.widget.Toolbar
          android:id="@+id/detail_toolbar"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:background="#fff"
          android:elevation="2dp"
          android:minHeight="60dp"
          android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
          app:layout_constraintLeft_toLeftOf="parent"
          app:layout_constraintRight_toRightOf="parent"
          app:layout_scrollFlags="scroll|enterAlwaysCollapsed"
          app:popupTheme="@style/ThemeOverlay.AppCompat.Light"&gt;
  
          &lt;LinearLayout
              android:layout_width="wrap_content"
              android:layout_height="match_parent"
              android:layout_gravity="center"
              android:gravity="center"
              android:orientation="vertical"&gt;
  
              &lt;TextView
                  android:id="@+id/evt_title"
                  fontPath="fonts/PanameFY.otf"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_gravity="center"
                  android:textAlignment="center"
                  android:textColor="@color/black"
                  android:textSize="30sp" /&gt;
  
              &lt;LinearLayout
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"&gt;
  
                  &lt;TextView
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:layout_gravity="center"
                      android:padding="2dp"
                      android:text="Organizer's level:"
                      android:textAlignment="center"
                      android:textColor="@color/black"
                      android:textSize="12sp" /&gt;
  
                  &lt;ImageView
                      android:id="@+id/org_level"
                      android:layout_width="60dp"
                      android:layout_height="16dp"
                      android:layout_gravity="center_vertical" /&gt;
              &lt;/LinearLayout&gt;
  
              &lt;TextView
                  android:id="@+id/optional_title"
                  fontPath="fonts/PanameFY.otf"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_gravity="center"
                  android:padding="2dp"
                  android:textAlignment="center"
                  android:textColor="@color/black"
                  android:textSize="24sp"
                  android:visibility="gone" /&gt;
  
          &lt;/LinearLayout&gt;
  
      &lt;/android.support.v7.widget.Toolbar&gt;
  
  
      &lt;android.support.v4.widget.NestedScrollView
          android:id="@+id/scrollv"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          app:layout_constraintTop_toBottomOf="@+id/detail_toolbar"&gt;
  
          &lt;android.support.constraint.ConstraintLayout
              android:layout_width="match_parent"
              android:layout_height="match_parent"&gt;
  
  
              &lt;ImageView
                  android:id="@+id/activity_image"
                  android:layout_width="0dp"
                  android:layout_height="wrap_content"
                  android:adjustViewBounds="true"
                  app:layout_constraintHorizontal_bias="0.0"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
  
                  app:srcCompat="@color/black" /&gt;
  
              &lt;TextView
                  android:id="@+id/month"
                  android:layout_width="70dp"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="8dp"
                  android:text="NOV"
                  android:textAlignment="center"
                  android:textColor="@android:color/holo_red_light"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/activity_image" /&gt;
  
              &lt;TextView
                  android:id="@+id/day"
                  android:layout_width="70dp"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="2dp"
                  android:text="15"
                  android:textAlignment="center"
                  android:textColor="@color/black"
                  android:textSize="24sp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/month" /&gt;
  
              &lt;TextView
                  android:id="@+id/starts"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="8dp"
                  android:text="Starts"
                  android:textColor="@color/black"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toRightOf="@+id/month"
                  app:layout_constraintTop_toBottomOf="@+id/activity_image" /&gt;
  
              &lt;TextView
                  android:id="@+id/ends"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="7dp"
                  android:text="Ends"
                  android:textColor="@color/black"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toRightOf="@+id/day"
                  app:layout_constraintTop_toBottomOf="@+id/starts" /&gt;
  
              &lt;TextView
                  android:id="@+id/start_date"
                  fontPath="fonts/AvenirNext-Medium.ttf"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="42dp"
                  android:layout_marginStart="42dp"
                  android:layout_marginTop="8dp"
                  android:text=" 18:10   Wed, Nov 15"
                  android:textColor="@color/black"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toRightOf="@+id/starts"
                  app:layout_constraintTop_toBottomOf="@+id/activity_image" /&gt;
  
              &lt;TextView
                  android:id="@+id/textView34"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="50dp"
                  android:layout_marginStart="50dp"
                  android:layout_marginTop="7dp"
                  android:textColor="@color/black"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toRightOf="@+id/ends"
                  app:layout_constraintTop_toBottomOf="@+id/start_date" /&gt;
  
              &lt;View
                  android:id="@+id/view10"
                  id="@+id/view8"
                  android:layout_width="0dp"
                  android:layout_height="1dp"
                  android:layout_marginTop="16dp"
                  android:background="@color/thegray"
                  app:layout_constraintHorizontal_bias="0.0"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/linearLayout2" /&gt;
  
              &lt;View
                  android:id="@+id/view9"
                  android:layout_width="0dp"
                  android:layout_height="1dp"
                  android:layout_marginTop="9dp"
                  android:background="@color/thegray"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/textView34" /&gt;
  
              &lt;LinearLayout
                  android:id="@+id/linearLayout"
                  android:layout_width="397dp"
                  android:layout_height="wrap_content"
                  android:layout_marginTop="25dp"
                  android:orientation="horizontal"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/textView34"&gt;
  
                  &lt;ImageView
                      android:id="@+id/requests_image"
                      android:layout_width="24dp"
                      android:layout_height="24dp"
                      android:layout_weight="1"
                      app:srcCompat="@drawable/requestsicon" /&gt;
  
                  &lt;ImageView
                      android:id="@+id/invite_image"
                      android:layout_width="24dp"
                      android:layout_height="24dp"
                      android:layout_weight="1"
                      app:srcCompat="@drawable/invitefriends" /&gt;
  
                  &lt;ImageView
                      android:id="@+id/recommend_image"
                      android:layout_width="24dp"
                      android:layout_height="24dp"
                      android:layout_weight="1"
                      app:srcCompat="@drawable/recommend" /&gt;
  
                  &lt;ImageView
                      android:id="@+id/share_image"
                      android:layout_width="24dp"
                      android:layout_height="24dp"
                      android:layout_weight="1"
                      app:srcCompat="@drawable/shareblue" /&gt;
              &lt;/LinearLayout&gt;
  
              &lt;LinearLayout
                  android:id="@+id/linearLayout2"
                  android:layout_width="396dp"
                  android:layout_height="wrap_content"
                  android:orientation="horizontal"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/linearLayout"&gt;
  
                  &lt;TextView
                      android:id="@+id/requests_text"
                      fontPath="fonts/avenir-next-bold.ttf"
                      android:layout_width="24dp"
                      android:layout_height="wrap_content"
                      android:layout_weight="1"
                      android:text="Requests"
                      android:textAlignment="center"
                      android:textColor="@color/black"
                      android:textSize="12sp" /&gt;
  
                  &lt;TextView
                      android:id="@+id/invite_friends_text"
                      fontPath="fonts/avenir-next-bold.ttf"
                      android:layout_width="24dp"
                      android:layout_height="wrap_content"
                      android:layout_weight="1"
                      android:text="Invite friends"
                      android:textAlignment="center"
                      android:textColor="@color/black"
                      android:textSize="12sp" /&gt;
  
                  &lt;TextView
                      android:id="@+id/recommend_event_text"
                      fontPath="fonts/avenir-next-bold.ttf"
                      android:layout_width="24dp"
                      android:layout_height="wrap_content"
                      android:layout_weight="1"
                      android:text="Recommend"
                      android:textAlignment="center"
                      android:textColor="@color/black"
                      android:textSize="12sp" /&gt;
  
                  &lt;TextView
                      android:id="@+id/share_text"
                      fontPath="fonts/avenir-next-bold.ttf"
                      android:layout_width="24dp"
                      android:layout_height="wrap_content"
                      android:layout_weight="1"
                      android:text="Share"
                      android:textAlignment="center"
                      android:textColor="@color/black"
                      android:textSize="12sp" /&gt;
              &lt;/LinearLayout&gt;
  
              &lt;TextView
                  android:id="@+id/status_text"
                  fontPath="fonts/avenir-next-bold.ttf"
                  android:layout_width="0dp"
                  android:layout_height="wrap_content"
                  android:layout_marginTop="16dp"
                  android:paddingLeft="8dp"
                  android:textColor="@color/dark_gray"
                  android:textSize="20sp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/view10" /&gt;
  
              &lt;ImageView
                  android:id="@+id/is_for"
                  android:layout_width="36dp"
                  android:layout_height="36dp"
                  android:layout_marginLeft="8dp"
                  android:layout_marginStart="8dp"
                  android:layout_marginTop="6dp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/status_text"
                  app:srcCompat="@drawable/maleandfemale" /&gt;
  
              &lt;TextView
                  android:id="@+id/going"
                  fontPath="fonts/AvenirNext-Medium.ttf"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="8dp"
                  android:layout_marginStart="8dp"
                  android:layout_marginTop="15dp"
                  android:text="going"
                  android:textColor="@color/black"
                  app:layout_constraintLeft_toRightOf="@+id/is_for"
                  app:layout_constraintTop_toBottomOf="@+id/status_text" /&gt;
  
              &lt;TextView
                  android:id="@+id/more_togo"
                  fontPath="fonts/AvenirNext-Medium.ttf"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="20dp"
                  android:layout_marginStart="20dp"
                  android:layout_marginTop="15dp"
                  android:text="TextView"
                  android:textColor="@color/black"
                  app:layout_constraintLeft_toRightOf="@+id/hor_view"
                  app:layout_constraintTop_toBottomOf="@+id/status_text" /&gt;
  
              &lt;View
                  android:id="@+id/hor_view"
                  class="android.support.v4.widget.Space"
                  android:layout_width="1dp"
                  android:layout_height="30dp"
                  android:layout_marginLeft="35dp"
                  android:layout_marginStart="35dp"
                  android:layout_marginTop="8dp"
                  android:background="@color/dark_gray"
                  app:layout_constraintLeft_toRightOf="@+id/going"
                  app:layout_constraintTop_toBottomOf="@+id/status_text" /&gt;
  
              &lt;android.support.v7.widget.RecyclerView
                  android:id="@+id/participants_list"
                  android:layout_width="0dp"
                  android:layout_height="117dp"
                  android:layout_marginTop="12dp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/hor_view" /&gt;
  
              &lt;View
                  android:id="@+id/view16"
                  android:layout_width="0dp"
                  android:layout_height="1dp"
                  android:layout_marginTop="8dp"
                  app:layout_constraintHorizontal_bias="0.0"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/participants_list" /&gt;
  
              &lt;TextView
                  android:id="@+id/textView47"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="17dp"
                  android:text="Costs"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/view16" /&gt;
  
              &lt;TextView
                  android:id="@+id/cost_text"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginEnd="8dp"
                  android:layout_marginRight="8dp"
                  android:layout_marginTop="17dp"
                  android:text="TextView"
                  android:textSize="18sp"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/view16" /&gt;
  
              &lt;View
                  android:id="@+id/view19"
                  android:layout_width="0dp"
                  android:layout_height="1dp"
                  android:layout_marginTop="55dp"
                  app:layout_constraintHorizontal_bias="0.0"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/view16" /&gt;
  
              &lt;TextView
                  android:id="@+id/cost_title_text"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="13dp"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/view19" /&gt;
  
              &lt;View
                  android:id="@+id/view20"
                  android:layout_width="0dp"
                  android:layout_height="1px"
                  android:layout_marginTop="16dp"
                  android:background="@color/thegray"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintRight_toRightOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/view19" /&gt;
  
              &lt;ImageView
                  android:id="@+id/imageView15"
                  android:layout_width="40dp"
                  android:layout_height="40dp"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="16dp"
                  android:padding="8dp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/view20"
                  app:srcCompat="@drawable/pinblue" /&gt;
  
              &lt;TextView
                  android:id="@+id/textView50"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="7dp"
                  android:layout_marginStart="7dp"
                  android:layout_marginTop="16dp"
                  android:text="Event location"
                  android:textColor="@color/colorPrimary"
                  android:textSize="18sp"
                  app:layout_constraintLeft_toRightOf="@+id/imageView15"
                  app:layout_constraintTop_toBottomOf="@+id/view20" /&gt;
  
              &lt;ImageView
                  android:id="@+id/imageView5"
                  android:layout_width="40dp"
                  android:layout_height="40dp"
                  android:layout_marginLeft="16dp"
                  android:layout_marginStart="16dp"
                  android:layout_marginTop="16dp"
                  android:padding="8dp"
                  app:layout_constraintLeft_toLeftOf="parent"
                  app:layout_constraintTop_toBottomOf="@+id/textView50"
                  app:srcCompat="@drawable/background" /&gt;
          &lt;/android.support.constraint.ConstraintLayout&gt;
  
      &lt;/android.support.v4.widget.NestedScrollView&gt;
  
  
      &lt;android.support.v7.widget.CardView
          android:layout_width="0dp"
          android:layout_height="60dp"
          android:layout_marginBottom="29dp"
          android:layout_marginEnd="40dp"
          android:layout_marginLeft="40dp"
          android:layout_marginRight="40dp"
          android:layout_marginStart="40dp"
          app:cardBackgroundColor="@color/colorPrimary"
          app:cardCornerRadius="18dp"
          app:cardElevation="16dp"
          app:layout_constraintBottom_toBottomOf="parent"
          app:layout_constraintHorizontal_bias="0.0"
          app:layout_constraintLeft_toLeftOf="parent"
          app:layout_constraintRight_toRightOf="parent"&gt;
  
  
          &lt;TextView
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_gravity="center_vertical|center_horizontal"
              android:text="REQUEST TO JOIN"
              android:textColor="@android:color/white"
              android:textSize="14dp" /&gt;
      &lt;/android.support.v7.widget.CardView&gt;
  &lt;/android.support.constraint.ConstraintLayout&gt;
  </code></pre>
  
  <p>Someone pleeeease for the love of god explain this sh*t to me.</p>