If you are lunching more then one client at a time when this happens try increasing the time between lunching clients. You should be able to set that if you scroll down in the settings menu at the bottom of the General tab.
If you are lunching one client and getting that then try disabling any Test servers, if the launcher is updating them while your trying to lunch the game it might cause some issues.
Still no luck? Delete tq and ResFiles again. Could not copy files to tq means the launcher tried extracting resource files from ResFiles into the tq folder but was denied access for some reason or failed to write to disk for some reason. Either because the file was in use or because of a permission issue. By deleting the folders and having the launcher recreate them then that should solve the issue in either case.