Did not save an aia; that limits what you can do. You will have to find the errors and fix them.
You said several years old..AI2 was born in lat 2013. Are these AI Classic apps you are trying to access or are these Projects actually on your list of AI2 Projects? If these are AI projects, they need to be converted to ai2 formati ... use the ai to ai2 converter . Not all projects are convertable.
Are you testing these Projects on the device using WIFI or on the emulator? The current version of Companion is 2.36 . Is 2.36 what you are using? The problem might be as simple as updating Companion.
Instead of Firefox, you might try using Chrome..sometimes switching browsers performs miracles...sometimes.
Sorry, you cannot create an aia from an apk.
Regards,
Steve