https://bugs.winehq.org/show_bug.cgi?id=48006
--- Comment #34 from Andrew Church achurch+wine@achurch.org --- Just for the record, this bug is still present as of wine-9.0, and the same workaround (copy dlls/{jscript,mshtml} from the Proton 8.0 branch) still works.
Hopefully Proton will update to 9.0 soon and I'll be able to collect a set of commits that apply cleanly to wine HEAD.