Could I DM you a copy of a place that is also having this issue (if it helps)? Recently my game Project Stands 2 has also been experiencing crashes with similar use cases of ViewportFrames. The error message is the same and players are being disconnected.
I recently made a post on this in #help-and-feedback:scripting-support here regarding the issue and was re-directed here. I have a place file of the whole game available if needed. I can see that you responded a while ago but the issue doesn’t seem to be fixed (I understand that the staff is most likely on vacation and it’ll take a little longer to respond). My game uses both worldmodel’s and viewportframes.
Edit: buildthomas told me what to do so:
https://devforum.roblox.com/t/frequent-server-crashes-with-error-code-277/961771