osu! hangs when the editor is opened with a custom ruleset selected in the top bar

[Silver-Volt4]

Describe the bug:
Decided to check out the editor. Game pulled a uno reverse card and froze, because I forgot to switch rulesets.
This has likely been reported already, but I haven't found any issues on this, so I'm either a terrible googler, or this is a new bug.
Screenshots or videos showing encountered issue:

osu!lazer version:
https://github.com/ppy/osu/releases/tag/2021.424.0
Logs:
This is basically the only thing that will interest you:
2021-04-28 15:55:20 [error]: System.ArgumentException: Only beatmaps in the osu, taiko, catch, or mania rulesets can be encoded to the legacy beatmap format. (Parameter 'beatmap')
Attached the full runtime.log just in case.
runtime.log
I suggest that the game just says "nope" when the user tries to open the editor with a custom ruleset.

[frenzibyte]

Yes, there's no support for creating and editing beatmaps of custom rulesets yet.

I guess the UX could be improved a little bit to not lock itself in the editor screen and crash like that.

[peppy]

I think this is going to need to depend on #10314, and getting a non-legacy encoding path in place.

[Silver-Volt4]

I guess the UX could be improved a little bit to not lock itself in the editor screen and crash like that.

This seems to be resolved for me, the game no longer crashes. I can do Alt-Home from the broken screen and continue using osu! without further issues.