I've seen a couple of reports like this lately. Are you using any third party extension that might be affecting Roll20 behavior? My first guess is that since there have been a few reports, but the board is not swamped with reports, is that there is some common, but not universal factor involved. This is usually an extension, or non-supported browser. I'd suggest going through the troubleshooting steps I'll post below the line, and i that doesn't root out the cause, file a Help Center Request along with what you have tried, a link to the game, and best of all, a Console Log ( Chrome , Firefox ) from the time in which you attempted to launch the charactermancer. Could you please carefully work through these steps of our guide to Solving Technical Issues ? Step 1: Make sure to use the right browser Please check if these issues persist when using both Chrome and Firefox. Step 2: Ensure that there are no extensions/addons interfering with Roll20 Please disable all add-ons/extensions. Step 3: Clear your cache If none of the above succeeds, please thoroughly work through Step 4 . (Don't forget the complete Console Log!) Thank you!