urlalias_iri causes a lot of problems with german umlauts:

webdav is not working properly, IE and Firefox don't behave the same when it comes to url handling.

even images don't work properly in nodes with umlauts when transformationGroup=urlalias_iri

Steps to reproduce

Create a folder with name "ÄÜÜUÖ", put in an article an upload an image. edit the article and discard the draft. the result is the image is not shown in frontend and in administration when you edit the article again, although there is databasentry for the image.

fix is change
TransformationGroup=urlalias_iri to

TransformationGroup=urlalias_compat in site.ini

and run bin/php/updateniceruls.php