[Bug 51332] New: steamwebhelper.exe crashes, steam client totally unusable

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=51332

Bug ID: 51332
           Summary: steamwebhelper.exe crashes, steam client totally
                    unusable
           Product: Wine
           Version: 6.11
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: mfplat
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Each steamwebhelper.exe process stops immediately with this error message:

wine: Call from 7BC522E1 to unimplemented function
mfplat.dll.MFLockSharedWorkQueue, aborting
wine: Unimplemented function mfplat.dll.MFLockSharedWorkQueue called at address
7BC522E1 (thread 0384), starting debugger...

I don't know why it does this, because dlls/mfplat/libmfplat.def defines this
function as an alias to rtworkq.RtwqLockSharedWorkQueue, which seems to be
implemented.

Since all of the tabs in the steam client are web views, the whole client is
unusable.

Steam client version: Jun 8 2021