If I send out a bomber and then Undo the command before it is done with its run, my game locks up. I have to Alt-tab and end the task.
Known issue? Reporting in any case - maybe check it in PR.

For some reason I find myself reproducing this bug regularly, even though I know about it and it drives me crazy... just my style or command I guess. Do that! No, I mean that! Never mind, do the first thing again!

Yeah, it's a known issue. Unfortunately, the devs have been so tied up with MAPR that they haven't been able to fix it yet.

it also happens if you press skip while bombs are falling.

or if you try to undo/skip any other unit while the bombs are falling (or change another units target etc..)