This issue reproduces in a clean project - using engine’s launcher version 4.16.2
Working with blueprints on a multiplayer project.
Once I run the game with the “Dedicated Server” flag checked it becomes impossible to Undo blueprint changes (Ctrl+Z) from that point on.
Restarting the editor resets this behavior but it will happen again once you run again with a dedicated server.
The issue is similar to that discussed in this forum post: Undo/Redo doesn't work after playing - Community & Industry Discussion - Unreal Engine Forums
At the end of the post LemmyRamone mentions the exact same problem.
This was quite a few engine versions ago and it seems it is still happening.
Either no one is developing multiplayer games using UE4 and blueprints or I have no idea how it would be possible that such a critical bug would persist for so long.
Needless to say it becomes nearly impossible to develop anything without basic undo ability.
Please help out ASAP.
Thanks in advance,
Jake.