I can open the mod via the Options menu (like before) but over the past few weeks when the viewer is about to display the map it suddenly closes and I can't recover the file. Exporting the maps don't help because the maps need to be viewed via the CSL Map viewer. So what should I do? (I don't see any .log files in the <SteamApps>/common/Cities_Skylines directory like you posted on the mod's front page.