XMP modification in Xnview 1.98.5

[domviller]

I’m using the EXIF/IPTC data to organize my photos. By mistake I used the wrong description for many pictures. I could change the values for the EXIF/IPTC fields. However, the XMP field „description“ keeps the old/first value. No chance to modify XMP or to disable XMP creation. The checkbox „create XMP“ within the IPTC menue cannot be disabled (faded out).
As Picasa Webalbum use the XMP value „description“ I now have to manually modify the description within Picasa, picture by picture.
Is there a possibility to a) delete/disable XMP or b) to modify XMP values XMP?
rgds
domviller

[xnview]

If the checkbox is greyed, so you have not the plugin to write XMP...
If you want to erase XMP, you have Metadata>Clean