A Microsoft file hosting and synchronization service.
Hi
That file belongs to OneDrive, and this usually means part of the OneDrive installation or its codec files has become corrupted.
First press Windows + R, paste this command, then press Enter:
%localappdata%\Microsoft\OneDrive\OneDrive.exe /reset
Then open OneDrive again from the Start menu. Microsoft’s reset instructions are here: https://support.microsoft.com/en-us/onedrive/reset-onedrive
If the error returns, go to Settings > Apps > Installed apps, uninstall Microsoft OneDrive, restart the PC, then reinstall the latest version. Uninstalling OneDrive does not delete files stored in your OneDrive account.
Official reinstall instructions: https://support.microsoft.com/en-us/onedrive/reinstall-onedrive
I would not download swscale-9.dll separately from a DLL website, as reinstalling OneDrive is the safer fix.