Hmm. Can you define what "A lot of spells" is? 20 is a lot of spells. 50 is too many spells and can lead to lag or undesireable behavior. Also, which sheet are you using? Without any info, the usual sheet is D&D 5th Edition by Roll20 Sheet, but that's not a foregone conclusion. Is it a PC or NPC sheet? Once you have verified that it is not simply a case of a massively spell-bloated sheet, here are standard troubleshooting steps to go through. They might help isolate the source of the issue. 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!)