If your Arcane Legends app installed in your SD card, try this

1. Move it to Device ( setting,application,arcane lagends,move to device)
2. Start AL, wait until all patch update finish.
3. Login as normal

This steps worked for me. I tried to move it back to SD card and start it, but application automatic close/quit. So i kept this app on my device and no problem after that, i can play AL again..

My device, samsung galaxy tab 1 (P1000).