Every time I try to open my light room I get a"catalog can not open because it is open in another light room program"window and it tells me to either choose a different catalog or create a new one. I have tried both of these options as well as restarted my PC, uninstall and reinstall both the light room and the adobe creative cloud, and logging in and out. any other way I could possibly fix the problem this is the only creative cloud app that does this.
Open the folder that contains your Lightroom catalog. In that folder you should find a file with the same name as your catalog, but with the lock extension. That lock file needs to be deleted, and then Lightroom will start normally. The file is generated by the database engine when Lightroom is opened. On rare occasions the file can be left behind when Lightroom closes. When that happens the file has to be deleted manually.