We had a friend use the repair function for wow classic tbc after we had LOTS of trouble with zoning in dungeons. he tried to repair his game, the process finished almost completely and then said it couldnt finish repairing because it was already running. If he clicked the button again, multiple pop-up box said it was already running. Deleted bnet launcher, problem persisted. manually deleted all TBC files, problem persisted, deleted the files in c:/program data/bnet. Then he could click the button, if he tried to reinstall, it would still keep saying it couldnt because it was still repairing.
So I did the same this morning because I also had alot of issues of zonning in/out of dungeons. Exactly the same problem happened when deleting/uninstalling both the game and bnet launcher. Scanned the game and after a few minutes, “Repair failed because it is already running”, deleted the game manually, uninstalled bnet, reinstalled bnet launcher, same error keeps happening “Repair tool is already running”. deleted the c:/program data/bnet folder. If i tried to install the game in the same folder is with (with wow retail), bnet launcher bricked and said ti was still repairing (even tho it was uninstalled completely). The only way it worked is if I installed it in a different folder location.
The only thing that fixed it was delete the c:/program data/bnet and install the game in a different folder. Might wanna adress this becuase its highly frustrating and people who arent really tech savy will have major issues.