Possible issue with WASM and username encoding

[MSFS 2020] Bug Reports WASM
1

Wanted to report something that might potentially be a bug. A user from Turkey in our forum, reported a problem with a WASM module failing to load with this error:

WASM: Error -239 / ffffff11
WASM: ERR_FATAL_FILE_ERROR (-239 / ffffff11)

This doesn’t seem to be common but, a search on the MSFS users forum returned this:

So, I asked the user to provide his username and the locations where MSFS has been installed, which are standard for an MS Store installation:

C:\XboxGames\Microsoft Flight Simulator
C:\Users\Msı\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\Packages
C:\Users\Msı\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\Packages\Community

Now, please pay attention to his username, it’s not Msi (with a normal “i” at the end), it’s Msı, the letter at the end is not a regular “i”, but it’s the “Latin Small Letter Dotless I”, with a Unicode code of U+0131, and it’s binary encoded in UTF-8 as C4 B1

The user confirmed that, as soon as he changed his Windows username from Msı to Msi, using a regular “i” at the end, the problem was fixed and he was able to load the WASM module normally.

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2

This has also come up again recently for some of our users, but I didn’t get any confirmation of the fix yet like you did.

This is presumably the same issue that seemed to have been fixed some SU ago?

3

Wow, that is surprising. After all, Windows has been UTF-16-based for a very long time, one would think all APIs used by the simulator are Unicodes ones, not ancient “ANSI” ones, and that non-ASCII letters would not cause any problem.

4

The _A ones are actually back in favour now and the mechanism by which UTF-8 support has been added to the Win32 API Use UTF-8 code pages in Windows apps - Windows apps | Microsoft Learn. The “Beta version: Use UTF-8 for language compatibility” option mentioned in davux3’s topic above switches the system code page used by the _A APIs to UTF-8.

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5

Whoa, I had not been paying attention. UTF-8 is finally becoming a thing for real in Win32. Back in the days when I did Win32 coding, the UTF-8 codepage could mostly just be used for conversion between UTF-8 and UTF-16, if I recall correctly.

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6

Bumping this. We do still see occasional reports of this issue.

7

Hello,

This issue is tracked.
Thank you for reporting the problem.

Regards,
Sylvain

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