I'm trying to edit an APK file with APK Editor Studio 1.7.2 portable version. However, when I open the file, repack it, and try to install it on my phone, I get an "application not installed" error. 

I've edited several APKs before and they worked. However, the ones I've edited most recently (without making any changes) aren't working. I'm getting the error I mentioned. By the way, I'm trying to edit the Red Dead Redemption game. 

I sign APKs with my own signing key. 

Also, it's not just certain types of APK files that can't be installed. For example, there are APK files with two parts on the internet.I'm editing both of them; the first APK installs, but the second one, which I'm updating, doesn't install. It doesn't work when I edit the 1.53 single-part APKs. I was only able to get it to work with the 1.50 single-part APK version.

I solved the problem by using a new APK and trying MT Manager on my mobile device.