Leftover temp files in AppData\Local\Temp\CustomTempFonts in .NET

Converting certain files to HTML, results in leftover temp files in this location:
C:\Users\username\AppData\Local\Temp\CustomTempFonts

Attaching my sample project with a sample PDF:
GroupDocsTotal.zip (67.9 KB)

I don’t really think it’s specific to a project or any settings, maybe not even to a certain file.
We only encountered the issue on machine that were running Windows 10 or equivalent server OS.
On Windows 11, I can see that the folders and files are also created, but deleted right afterwards.
So something seems to be wrong with cleanup under Win 10.
Can you please check?

Hi @Clemens_Pestuka

This is a well-known and old bug (VIEWERNET-5060), it occurs only on .NET Framework 4.6.2 and only on some older revisions of Windows 10 and perhaps Windows 11 and only when opening PDF files. It is present in GroupDocs.Viewer and most of other GroupDocs products. Other our customers have also reported it, for example: Persistent CustomTempFonts Folder Growth Issue in GroupDocs.Viewer 24.6.0 and 24.9.0 for .NET Framework

We’re working on it and will notify you when it will be fixed. Sorry for the inconvenience.

With best regards,
Denis

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