Hi, its not the Microsoft clipboard history or sync. im using a third party tool called ditto, but it just records your clipboard and lets you search previous clipboard items. but i don't think the issue is due to the that software.
I do think the issue is related to clipboard items but i think its something else
I work in IT and am constantly remoting into other users computers through a software called screenconnect or "connectwise Control"
which also syncs clipboards from my machine to the remote machine and vice versa, it seems like something happens where the clipboard doesn't sync properly from the remote machine and makes my clipboard blank or perhaps some other sort of invalid value, and its when that happens and i try to move the other screen with multiplicity, that is causes the crash. as soon as clip something else the crashes stop.
I haven't been able to figure out exactly whats causing the clipboard items to go weird from a remote users machine. but i think if you catch or sanitize invalid clipboard values before trying to sync it to the other multiplicity machine that should help.