I’ve found some old notes about rooting a Motorola G4 Android phone and a puzzling issue I stumbled upon then. It may be useful to someone even though I couldn’t reproduce it now and don’t remember all the details.
I had a Moto G4 phone and it’s possible to officially unlock its bootloader in order to root it, remove some preinstalled (goog’s) crap and possibly install another firmware (Android is notoriously bad with software updates, Motorola was not very bad, they had occasional security updates). I followed one of the unlocking and rooting guides online: backed up as much stuff as I could (which is not much on a non-rooted phone), unlocked the bootloader by getting a code from Motorola, replaced the boot image, flashed TWRP, installed SuperSU, and replaced the kernel with ElementalX G4 because something didn’t work with the stock one.
Then I installed ABBYY Lingvo in the new system, but it was crashing on startup. I discovered that its directory on the internal storage (which I believe was in
/sdcard/Android/) was empty and was trying to
adb push it from the backup, but got “permission denied”. In fact, I couldn’t create any directory on
/sdcard/. The permissions and owner on the directory were correct. Searching online didn’t find a solution, I tried a number of things, even editing
platform.xml to change a setting. However when I booted into TWRP, I could write files to SD card fine.