Thanks in advance for reading because this is long.
tl;dr: I factory reset my rooted phone on VanirAOSP and now I can't download any apps or sync my accounts
My sister gave me her old Samsung Galaxy S3 (SGH - I747) last year, which is rooted and currently runs 5.1.1 on the Vanir ROM. It's been a bit buggy for a year but I'm lazy and she's more technologically savvy than I am so I just kind of dealt with the bugs.
Last week, the phone updated to 5.1.1. For some reason afterward, apps like Gmail, Google Play, Tumblr, Snapchat, etc. stopped working and whenever I would boot my phone, I'd receive a warning that the phone has an internal issue and that I should contact the manufacturer. I basically wasn't able to update any app and whenever I would open up a Google app like Gmail or Play, I'd see all of my accounts on the side but my the app would say I'm not connected to the internet (even if I was on wifi or 3G). Even though I would be able to go into Settings > Accounts > Google and see all of my accounts listed, I wasn't able to sync my contacts or anything.
Some Google apps, however, like Google Maps, Keep, Drive, etc. still did work so there wasn't a pattern that made sense to me. Other apps like Tumblr just wouldn't open. But Facebook, Dropbox, the stock email app, and others still functioned normally.
Because I hadn't done anything else to my phone other than update it, I assumed the issue was with the update or with the ROM. I tried flashing the phone back to Samsung's stock ROM but ran into issues on my computer. So I decided (somewhat hastily) to run a factory reset on my phone since all of my photos, texts, docs, etc. were backed up elsewhere.
Unfortunately, after the factory reset, I still would get the internal issue boot error and now no longer have Google Play installed on my phone and can't download any apps from the mobile web site (or from anywhere). The only apps I have are:
- Sound Recorder
This is weird because when my phone was booting up after the reset, it said it was optimizing 68 apps.
Now when I visit play.google.com/apps on my browser, I can see all of the apps I have ever installed on this phone or my old phone. When I go to Gmail, for instance, it will say the app is "Installed" (green button) and underneath will say "This app is compatible with your device." However, the app ISN'T on my phone at all. When I click on the green button, it opens up a page that tells me to "Choose a device" but the drop down only has my old HTC phone listed and not this Samsung phone. If I click "Install" with the HTC phone listed, I see "Congratulations! Gmail will be installed on your device soon." but that's also untrue. This happens both with apps I have downloaded before and apps I haven't.
After the reset, I attempted to flash the phone back to Samsung's stock ROM. I got farther this time and was able to start the process on Odin. However, the process kept failing and displaying a "FAIL (Auth)" error. One of the resources I found online said that I may not be able to flash back to a stock ROM if it's an older version of Android, which I'm pretty sure it is (KitKat).
So now I'm at a loss as to what to do. I've spent a lot of time Googling but haven't found anyone who has had a similar issue with their accounts/Google Play. Does anyone have advice as to what to try next? I'm basically willing to try anything that won't destroy the phone completely.