I had a problem on my PC where Plarium Play said it couldn't update properly. I uninstalled and tried to do a reinstall. I kept getting an "unrecoverable error" message.
Apparently, when you uninstall Plarium Play, Plarium folders are left behind that need to be deleted. Since I had installed Plarium with a local Admin account I created, I need to go to C:\Users\local_admin_acct\AppData\Local and C:\Users\local_admin_acct\AppData\LocalLow and delete the Plarium folders that existed.
When I re-installed Plarium Play, I selected Advanced Options and installed the game folders to a different location. After that the game works fine!!!
The info in this thread was what I tried. https://plarium.com/forum/en/raid-shadow-legends/674_game-discussion/202796_unrecoverable-error--don-t-know-what-to-do--please-help--/ I took their idea and also added on to it by loading the game to a different folder.