#132 Missing Microsoft.UI.Windowing.Core.dll error when using "Copy to Clipboard" on preset error

[Steven T Pippin]

Hi there,
I'm encountering a persistent error when using FFmpeg Batch AV Converter v3.2.5 on Windows 11. Specifically, when I click "Try Preset" on a preset that contains a deliberate error (to trigger the error screen), the app displays the expected error dialog. However, when I click "Copy to Clipboard" at the bottom of that dialog, I receive the following system error:

The code execution cannot proceed because Microsoft.UI.Windowing.Core.dll was not found. Reinstalling the program may fix this problem.

Here are the things that I have already tried to fix the issue:

1. Terminated and repaired the Notepad app
2. Terminated and reset Notepad
3. Ran sfc /scannow (found unrelated system file issues)
4. Installed the latest Windows App SDK (v1.8.0 — 1.8.250907003)
5. Fully uninstalled Notepad via app settings and PowerShell (Get-AppxPackage Microsoft.WindowsNotepad Remove-AppxPackage), then reinstalled via Microsoft Store
6. Uninstalled FFmpeg Batch AV Converter via Installed Apps, manually deleted residual folders
7. Reinstalled FFmpeg Batch AV Converter, updated to latest ffmpeg.exe, and re-imported presets

Despite all this, the error persists only when clicking “Copy to Clipboard” on the error dialog. Notepad itself launches fine otherwise, and the DLL Microsoft.UI.Xaml.dll is present on my system, in multiple locations. However, Microsoft.UI.Windowing.Core.dll is not found I'm attaching a screenshot of the locations of the file.

Can you help me resolve the issue?

[Abel]

Hi, I will fix this on next release, it could be related with forcing notepad to open the copied text.
This patched version should fix it: https://drive.upm.es/s/9Ty2yqmfgbrC2Rw/download

[Steven T Pippin]

Just wanted to say the patch worked perfectly. Your response is the gold standard of stewardship—clean, intentional, and legacy-safe. Thanks for building a tool that respects both power and simplicity. You’ve nailed it as Creator and Developer!

[Abel]

Thanks a lot for your kind words.
Cheers