if I use german mutations (e.g. öäüÖÄÜß) in gallery tags, the gallery doesn’t display the images.
Look at http://info.rethorn.de/galerie/ and chose the tag ‘Fingertipp & DaumenGrün’. That doesn’t work. Tagging with no mutations (like the tag ‘Fingertipp’) work.
Yes you are right. In this category there is used symbol ( & and ü ) in Fingertipp & DaumenGrün. So it is not working. So you need to add plain text to work no mutations and symbols.