Since y'all keep blowing up my eamail about this, I will shed SOME light on what's going on from what I can tell. It's the end of my work day, so you're getting grumpy Obu.
I'm not affected by this, but others in my guild are. Both iPhone and Android devices are affected and getting error code 3.0. ERROR CODE 3.0 IS A CREDENTAL ERROR ISSUE. We (as in the community nerds) first noticed this when they launched the web store and there were cred issues between the EA portal and the game. Once we started telling folks to reset their EA PW, it fixed the problem. That will not help here...
In my troubleshooting we have done the clear cache trick, the clear cache and remove app trick, the EA PW fix, and nothing seems to fix these devices. Most get to the google play log in or FB log in, do the sync, and it chokes on it's portions. My best guess is that there are issues between authentication portals and the game in general. Google and FB are both freaking out, so my guess is that it's on the EA/CG side of things.
Now, if you REALLY want to try this, your welcome to, but I make no guarantees this will work. Also, it's only for android...
1) Go into your app settings and find SWGOH
2) Clear you cache
3) Clear your app storage for swgoh.
4) UNINSTALL swgoh
5) reboot your phone
6) after reboot and go into the play store and reinstall SWGOH.
There is a SLIM chance that this may fix it, and if it does, let us know. My guess is it won't, but it's about as through as a remove and reinstall process as one can do with a locked android phone.