Occasionally, patching issues can occur when certain game files become corrupt. To repair corrupted files:
- Run GOG Galaxy.
- Click GWENT: Rogue Mage on the installed games' list on the left side.
- Press MORE button, select "Manage Installation" and then "Verify / repair".
- Wait. The repair function can take time depending on the number of corrupt files it has to repair.
- From the Library section, right-click on the game and select Properties from the menu.
- Select the "Local files" tab and click the "Verify integrity of game cache..." button.
- Steam will verify the game's files - this process may take several minutes.