CardView extension giving trouble

Hey there everyone
My app downloaded last night to check,everything was perfect, I made a batch of changes and am almost ready to finalise, except i am now getting this error on the apk. Everything works perfectly in the companion app, but this crashes in the built app.

If I remove all CardView calls, the app works just fine, but as soon as I add even one CardView, I get this error
I have deleted and reinstalled the extension multiple times, I'm at my wits end now please help me!