"This app won't run without Google Play Services which are missing from your phone" on Samsung Galaxy S2 I recently rooted my Galaxy S2 GT I9100 phone.

I search some of the video on YouTube about how to upgrade OS from Jelly Bean 4.1 to Lollipop 5.02. I did the same and succeed in it. 

The problem I'm facing right now that my phone has been updated to CyanogenMod Lollipop 5.1, but I'm not able to use any Google services Apps e.g. WhatsApp, Gmail, Google Maps, Youtube

I'm able to use pre-installed apps like Music Player, Dialer etc.

When I clicking on Play Store or any Google apps it is showing This app won't run without Google Play Services which are missing from your phone.

And 2nd Problem I'm facing is although it is updated to Lollipop, the phone is not starting like a Lollipop. When rebooting a blue Android appear and it is blinking and a yellow error sign or logo appears just below the Samsung Logo when the phone starts.

What should I do to use all the Google apps and phone work as it work in any other Lollipop Android phone?
You can do this the easy way by just (re)installing your Google Apps. Download the right GApps package from CyanogenMod / XDA / Goo.im and flash it in recovery.

OR you can also use the APKs linked on the site in your comment. This method is not recommended and may dump your phone into a bootloop!

You probably want to download this one. Install it by connecting your phone to PC (make sure USB debugging is enabled and that you have ADB installed on your PC) and typing these commands in a terminal:

adb push &lt;path to downloaded APK&gt; /sdcard/GmsCore.apk
adb shell
$ su
# mount -o rw,remount /system
# cp /sdcard/GmsCore.apk /system/app/GmsCore.apk
# chmod 0644 /system/app/GmsCore.apk
# rm /sdcard/GmsCore.apk
# mount -o ro,remount /system
# exit
$ exit


Then reboot your phone.