https://bugs.winehq.org/show_bug.cgi?id=49326
--- Comment #2 from Kimball kdt3rd@gmail.com --- Created attachment 67362 --> https://bugs.winehq.org/attachment.cgi?id=67362 patch that may help
Adding this and recompiling seemed to make the error and assert go away for me, but not sure if the above patch is correct, it seems like it's patching up a logic error - but hope this helps isolate what that logic error might be.