CanvasFontSet.GetSystemFontSet() throws when Microsoft Office 2019 with cloud fonts is open

[JohnnyWestlake]

Steps:

• Have Office 365 / 2019 installed with a subscribed Office 365 account with connected experiences enabled in account settings, which allows Office to download cloud fonts.
• Open Microsoft Word, and download a cloud font or two from the font dialog.
• Leave Word open
• Now run any Win2d app that calls CanvasFontSet.GetSystemFontSet() or call it your self.
• Observe the System.AccessViolationException you recieve: "Attempted to read or write protected memory. This is often an indication that other memory is corrupt."

Note that if you've had previous versions of Office installed without cloud fonts it may not show cloud fonts, as many of the cloud fonts were previously fonts installed by default with office.

Note that CanvasTextFormat.GetSystemFontFamilies(ApplicationLanguages.Languages) does not crash.

(Windows 10 18363.657, Win2D 1.24.0)

[0x7c13]

Even with "ApplicationLanguages.Languages", I am still seeing exception coming from GetSystemFontFamilies(ApplicationLanguages.Languages):

System.Exception: Unspecified error (Exception from HRESULT: 0x80004005) at System.Runtime.InteropServices.McgMarshal

Not sure why. It is only happening recently to my app users but not sure what is causing the issue here. I do not see System.AccessViolationException tho.

[JohnnyWestlake]

Honestly, out of the 3 devices I could reproduce this on when I first posted, none of them do it anymore. So either an Office update or a Windows Update has fixed my particular exception. (It was always a DirectWrite level issue rather than Win2D's abstraction anyway)