Help SM-901F acore process stopped

[RandomTrollface]

Hi guys,

I have a samsung galaxy s5+ running unofficial cm14 (dirty flashed from 13 yesterday), but after this update I constantly get the famous 'process.acore' has stopped issue. I tried looking in the forums for a solution but I couldn't find a working one.
I know the issue has something to do with contacts, whenever I try to open an app that uses the contact list (whatsapp, skype etc) it instantly stops, and even the contacts app itself can't be opened, so I tried clearing the contact data from the settings menu but it didn't work either, the contacts seem to be synced back instantly.

I rather do not want to clear my data partition unless it can be backup and restored easily (I'm not using backup apps now)

What should I do? I still have a cm13 TWRP backup but I really want to try android 7.0.

 

[RandomTrollface]

UPDATE: Because of even more unstability issues in cm14 I decided to go back to cm13 for now.
I only have 1 question and that is about TitaniumBackup, I've always dirty flashed major system updates without issues, but now I realize I might have to stop doing that.
So what if I make a titanium backup of all my cm13 (android 6) files, can I restore that backup in cm14 (android 7)? If not, is there another way for me to flash major updates without losing data?
Thanks in advance

 

[El Presidente]

Generally speaking dirty flashing from one version of the same ROM to another is ok, but if you do I'd recommend clearing the cache partitions before booting back in to the OS. When you dirty flash an upgrade from one android version to another, problems can occur (as you've found out).

CM14 is going to be unstable anyway as it's still a fairly new release.

As long as you only backup and restore user apps, they should be recoverable no matter what ROM you restore them on.

Don't backup system apps though, that can cause problems, similar to the one you mentioned in your first post.

Also make sure you have a decent nandroid backup to restore in case you encounter problems with the backups TB has made.