Clearing the chat archive has resolved my issue on a game by game basis, leaving the additional information below as it may still be relevant for others. Clearing the chat archive has resolved the symptoms, but the chat breaks immediately due to at least one macro on the character sheet. The following video shows easy steps to force the issue in a completely blank slate game: <a href="https://youtu.be/SrioFxRvQ7M" rel="nofollow">https://youtu.be/SrioFxRvQ7M</a> Currently having this issue with the Cypher Systems Sheet in two Campaigns. I'll DM Nicholas with the relevant links as per this post. Nicholas said: Hey folks! I just pushed out a hotfix for this issue and your character sheets should be good to go now. If you continue to run into trouble, please try to clear your chat archive and browser cache as part of the troubleshooting process. If that does not address the problem, please post or dm me a link to your game and I will look into it as soon as possible. Thank you! As to conditions: Windows 10 Pro 10.0.19042 Build 19042 Chrome Version 90.0.444.30.212 Official - 64 bit & Firefox Version 88.0.1 - 64 bit All addons disabled. All antivirus disabled. Attempted before and after PC restart. Chat went from looking normal to looking either empty or spam-repeating lines whenever new rolls or messages came from other players: Interestingly, it affected a campaign I wasn't currently playing in, but shared the character sheet template with this campaign. Interestingly, regardless of the fact that it fully broke later on, it appears that both cutoff points for what gets displayed now seems to be immediately after the "apply cost" macro link was applied, which could point towards an API issue. Restarting the API sandbox did not fix the issue. Perhaps stranger still, when inputting anything before, I would get spam of the same line in chat over and over like this: However, it now shows nothing and the chat remains blank. If you have any further questions don't hesitate to ask. Clearing the Chat Archive does appear to work, though I'd like to know if other solutions exist to fix it.