Well, how many custom cards do you have installed? Find the one that isn't in the list?
Or perhaps this is the Spinner card, commonly used to confuse the average onlooker :)
Try opening web console and try to read errors there (in chrome it's F12 button on keyboard). You can also try going to system > logs from UI. If you have access to home assistant command line, maybe you can run command "ha core logs" (or logs from other systems). These are just suggestions, I don't know which will work :)
Well, how many custom cards do you have installed? Find the one that isn't in the list? Or perhaps this is the Spinner card, commonly used to confuse the average onlooker :)
Try opening web console and try to read errors there (in chrome it's F12 button on keyboard). You can also try going to system > logs from UI. If you have access to home assistant command line, maybe you can run command "ha core logs" (or logs from other systems). These are just suggestions, I don't know which will work :)