AAPT: error: resource android:attr/lStar not found.

I ran the flutter Android project today and suddenly it stopped running.

Later it was discovered that it was caused by some plug-in upgrades.

They used androidx.appcompat:appcompat:1.4.0 corresponding core:1.7.0

implementation 'androidx.appcompat:appcompat:1.4.0'

solution:

Change the plug-in version to correspond to androidx.appcompat:appcompat:1.3.1 and corresponding core:1.5.0

implementation 'androidx.appcompat:appcompat:1.3.1'