I recently started seeing this error after upgrading my Android Studio version. After some debugging, I found out the solution, and it's pretty simple.
Plugin "Dart" is incompatible (target build range is 191.6707 to 191.*).
Plugin "Flutter" is incompatible (target build range is 191.6707 to 191.*).
Go to File -> Settings, then select Plugins from the left hand side. You want to make sure that Dart and Flutter is using the latest version and Enabled. Then restart Android Studio and everything should be working fine.