[WebP Filetype (2023-11-26)]

Have you installed the VC2010 SP1 runtime that the plugin requires?

Ah yes. After installed this runtime it works fine. Thanks for help and developing!

[WebP Filetype (2023-11-26)]

Have all three dlls been placed in the FileTypes folder?

Yep!

And no security access scanner is running.

Latest Windows Updates (Net.Framwork, etc) are installed.

Uninstalled and reinstalled Paint.Net. No other effects installed.

Only OptiPNG filetype installed.

[WebP Filetype (2023-11-26)]

Using Paint.Net 3.5.10 with your 1.0.0.3 Version.

No Preview available and when saving an unknown error message pops up.

Also cant open the example files from the latest WebP Codec for Windows (v0.17) package wich is

using the libwebp 0.2.0.

Try it with a 320x240 photo, bmp & jpg.

Win7 x64