Many people have a problem on Moto G that they cannot install APKs on the phone. Hopefully, there are few workarounds for this problem.
BEST SOLUTION: Make a wipe/data facotry reset. Then skip all the configuration process and jump to settings. Now enable option of installing non-market apps
1) Put the files you wish to install in /data/create_any_folder_here/<here> (needs root)
2) Upload your games/applications on Google Drive and install them from there
3) People are reporting that couple of wipes solve the problem...
4) Install APKs trough USB flash stick connected using OTG cable
P.S. The bug should be fixed in the next OTA update. French and German retail phones have the fix already.