I have been trying to upload new token markers (status indicators) into an existing set and Roll20 just hangs on this screen forever. I have done this many times in the past but this time it is not working. I have tried disabling all extensions, tried chrome, tried firefox, and also incognito / private browsing windows with no luck. Each token I am trying to upload is 512 x512 and around 60kb with transparent background saved as a .png file. Am I doing something wrong?