I'm sure this parsing package error is because the permissions for /storage are not set properly,
and for some reason can not be changed, they just revert after rebooting ?
this here is how they should be, (on my nexus 5)
and this is how they are on the Moto G
Since Motorola have supposedly fixed this in an OTA, i'm not going to waste any more time with this problem as i'm out of ideas anyway.
so for now... while we wait for the GB update (would not use the others available as they change modem files, which might be country specific)
here is an empty flashable.zip which you can open with winrar or 7zip and copy all your apk to it and flash in recovery (ideal for batch)
1.) open the .zip by double clicking on it
2.) open the data/app folder and drag & drop all your .apk onto it
3.) close, add to sdcard and flash in recovery (no wipes)
I can't understand why anyone would need to do this, the flashable zip solution, or indeed uploading apk's to dropbox....
Simply move or copy the downloaded apk to / .....your internal memory root, with a root explorer, and flash from there...you can delete the apk after installation.
I have not found any apk which refuses to install in that location, even though they give the parsing error in the downloaded location, on /mnt/sdcard wherever the apk is by default when downloaded.