Undo Bug with Smulation environment

[alan.jonesXHXUF]

If you have been performing a simulation, the go and make some edits or whatever to the model and then undo to a point that lands back in the simulation workspace, the toolbar disappears. 

https://www.youtube.com/watch?v=DRKLjYMkm0E&ab_channel=AlanJones

[Steven_Gao]

Thanks for reporting this problem! Yes, it is reproducible on the latest version. I have logged an internal defect(FUS-109418) to track it now. Will let you know if there is any update of it.

Thanks again!

Steven