Hmm. Without more info, I can only offer guesses. What is the name of the character? In very weird cases (usually but not always names containing diacritical characters or punctuation) the name itself can through an error. You could try temporarily renaming the character something like "Bob" and see if it still throws up the error. If that doesn't help, you'll probably need to go through the 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!) If a mod hasn't responded once you've done that, you can flag your post for mod attention (report it using the report button--don't worry, you won't get in trouble). They should be able to handle it from there.