https://bugs.winehq.org/show_bug.cgi?id=34544 --- Comment #15 from Esme Povirk <madewokherd(a)gmail.com> --- I found source code: https://github.com/webkitdotnet/webkitdotnet/blob/5a67dae661c15f9da92ec57f13... WebViewClass.initWithFrame is from a COM wrapper. I can't find the source code, but since the error comes from ThrowExceptionForHR, I think we can assume it's from the underlying COM object. Apparently, InvalidCastException corresponds to E_NOINTERFACE. Which means it's likely due to this error in the log: 0024:err:ole:CoMarshalInterface Failed to marshal the interface {00000122-0000-0000-c000-000000000046}, hr 0x80004002 -- Do not reply to this email, post in Bugzilla using the above URL to reply. You are receiving this mail because: You are watching all bug changes.