We have a share folder where we keep extensions and software files. I think someone replaced files there.
The source code of this extension is available on Github. I cloned it and changed the range of visual studio version in installation targets in source.extension.vsixmanifest. Previously, range was 11 to 17, I changed it 11 to 22 and also updated the product architecture to amd64. I rebuilt it, hence, the extension file names as CLIPSLanguage.vsix was updated in bin/debug folder. I double clicked it and it got installed for VS 2022.