Downgrading 9.0.83 Google Play Services manually I got the following log error in my route tracking activity


  06-24 18:50:24.488 7128-7759/com.noureddine_ouertani.www.wocelli50
  E/DynamiteModule: Failed to load module descriptor class: Didn't find
  class
  "com.google.android.gms.dynamite.descriptors.com.google.android.gms.googlecertificates.ModuleDescriptor"
  on path: DexPathList[[zip file
  "/data/app/com.noureddine_ouertani.www.wocelli50-2/base.apk"],nativeLibraryDirectories=[/vendor/lib64,
  /system/lib64]]


After reading some posts and answers  about this log error I figured out that it's a known Google Play Services version  9.0.83 issue that causes bugs in some apps that use a GoogleApiClient like mine.

However I didn't test the solution yet. I wanted to downgrade Google Play Services on my Smartphone but Uninstall Updates was greyed out (see Screenshot).



Does anyone know how to do this manually?

I installed the Android Device Manager app but found no possibility to influence the stop/uninstall updates buttons of Google Play Services. Then I tried to apply this solution but the System App Remover app got no root permission on my Smartphone.

Any hints or help?
I solved the problem for my Huawei P8 Lite Android phone like this:


I unlocked my bootloader 
I rooted my phone 
I succesfully checked with Root Checker Basic that my phone is rooted
I downloaded and installed System App Remover from the Google Play Store.
I put my device in Airplane Mode in order to prevent auto upgrade of GPS.
I opened System App Remover and select "System App" from the menu.
After I found Google Play Services in the list which was marked as "Should keep" I selected it and pressed "Uninstall". I ignored the next warning.
Using Settings/Apps, I saw that Google Play Services "Uninstall Updates", and "Disable" Buttons were no longer be grayed out.
I pressed "Uninstall Updates"


Here is the result: Downgrade of Google Play Services to 8.1.18