Android Studio 4.1 keep showing plug in incompatible error even if that plugin was uninstalled

Windows 10

Go to path %APPDATA%\Google\AndroidStudio4.1\plugins and remove manually undesired plugins folders and/or .jar files.

Linux

I had the same issue, removing the unsupported plugins in the the config folder fixed it (you can also remove the entire configuration folder, a new one will be re-created).

For linux, the new configuration path is:

~/.config/Google/AndroidStudio4.1

There is also other non-configuration folders at the following paths:

~/.local/share/Google/AndroidStudio4.1

~/.cache/Google/AndroidStudio4.1

I fixed it! Look like the uninstall button in the plugin GUI screen is just for decoration purpose only, the plugin is still in the /Users/your_username/Library/Application Support/Google/AndroidStudio4.1/plugins. After removing the plugin folder manually everything is back to normal.