Android apk "App not installed": The package appears to be corrupt.

I have tried using the automatic, forced internal, and external install locations, have tried different keystores, have my package name in the right format (com.matthew.qualitycontrol) and have tried the gradle, internal, and adt build systems. I’m at a loss for why these apks are coming out as corrupt when i try to install them on my device.

one way that i had problem like this was when i wanted to install an app with special setting while there was already another one with different setting ( like “keystore”) installed on the device;

so check it if there is not any thing installed via app manager;

hello! could you found a solution?? same here :(. @mgiga0420