Just tried to run an app I wrote a while back, and it suddenly crashes with an error that says it can't find the MainActivity on the classpath. I haven't updated the code in a few months, and it worked last I uploaded code. Has anyone seen this before?

Usually the thing that older apps need is to remove the

package=<http://com.example.app|com.example.app>

attribute from the AndroidManifest.xml and put it in build.gradle:

android {
    namespace "<http://com.example.app|com.example.app>"
    ...
}

Ive had this happen where I just do a gradle clean and reinstall

Looks like a gradle clean and reinstall worked. I wonder what happened to the apk?