Undo Ceases to Function in Map Editor

[Cosmonaut_]

After a random number of changes in the map editor, the undo button will no longer work. Tested by moving a brush and then undoing the movement until I lose the ability to undo. I've recorded the undo functionality breaking at 7 changes, 16 changes, 24 changes, and 40 changes, so unfortunately I don't see a pattern to speak of, and it happens annoyingly frequently. Reloading the map (.ultra) file resets the undo function. I'm using the Steam version, currently on the beta branch (Build 867).

[reepblue]

This is a known issue and I try to bring it up to Josh every weekend.  

[Cosmonaut_]

I was looking through the other bug reports wondering how nobody had run into this issue yet lol

[Josh]

Problems that don't have a specific way to produce them unfortunately are harder to resolve.

[reepblue]

59 minutes ago, Josh said:

Problems that don't have a specific way to produce them unfortunately are harder to resolve.

That's what's aggravating about this. When you battle test the undo system, it seems to work fine but when you're the middle of a mapping session, the undo system lets you down. 

I don't even know how you could debug this without doing a remote debugger on them while they map. I can try to find step by step examples, but watch it be fine on your end.