Possible MacOS fix
This is from Oracles discord announcement
Hi, Raiders! Here is some news for those users who experience problems with launch of the game on MacOS. Please, try to delete all files in the folder:
*~/Library/Application Support/com.plarium.raidlegends/BattleJournals*. We have reports from people whom it actually has helped to deal with the issue
You may use an option "Go to Folder..." and paste the path to the folder specified above in order to find it