@all
MUI4 has a public bugtracker (
https://muidev.de/newticket) and also a big fat petition to report any bugs there on the very first page of MUI prefs. Is it really that hard to actually USE that bugtracker, instead of asking questions here? Even if an issue is confirmed by other users this will not fix the bug automagically as long as we don't know about it. And if there is a crash then at least the crashlog MUST be provided. Simply stating "it crashes" or "it doesn't work" is NOT enough and won't help anybody.
Anyway, I just fixed this issue. The next nightly build of MUI4 will include a fixed Popplaceholder.mcc. At least it does not crash any longer on AmigaOS3 for me anymore.
But please use the bugtracker IMMEDIATELY next time. Don't expect us to skim each and every forum for possible bug reports.