`xdg-open` thinks I'm running WSL, and fails because I'm not? [duplicate]

When I try to open a pdf file with xdg-open file.pdf, I get the following error message:

jonas@jonas-thinkpad:~$ xdg-open file.pdf grep: /proc/sys/fs/binfmt_misc/WSLInterop: No such file or directoryWSL Interopability is disabled. Please enable it before using WSL.grep: /proc/sys/fs/binfmt_misc/WSLInterop: No such file or directory[error] WSL Interoperability is disabled. Please enable it before using WSL.jonas@jonas-thinkpad:~$ /usr/bin/wslview: line 216: /mnt/c/Windows/System32/reg.exe: No such file or directory/usr/bin/wslview: line 308: [: -ge: unary operator expected[error] This protocol is not supported before version 1903.

For some reason it tries to do WSL shenannigans? As I don't use Windows, I really don't understand why this happens. xdg seems to be configured to open pdf files with okular:

jonas@jonas-thinkpad:~$ xdg-mime query default application/pdfokularApplication_pdf.desktop

And this is what okularApplication_pdf.desktop looks like:

[Desktop Entry]MimeType=application/pdf;application/x-gzpdf;application/x-bzpdf;application/x-wwf;Terminal=falseName=OkularName[ar]=اوكلارName[az]=Okular--- omitted languages ---Name[zh_TW]=文件檢視_OkularGenericName=Document ViewerGenericName[ar]=عارضالمستندات--- omitted languages ---GenericName[zh_TW]=文件檢視器Comment=Universal document viewerComment[ar]=عارضالمستنداتعالمي--- omitted languages ---Comment[zh_TW]=通用文件檢視器Exec=okular %UIcon=okularType=ApplicationInitialPreference=8Categories=Qt;KDE;Graphics;Viewer;X-KDE-Keywords=PDF, Portable Document FormatX-KDE-Keywords[ar]=PDF, Portable Document Format--- omitted languages ---X-KDE-Keywords[zh_TW]=PDF, Portable Document FormatNoDisplay=true

Looks totally fine to me. Any clue what is going on here?