Oh, sorry, my English is not the best. I do
not solve the problem until today. I hope that's what I want to say.
But there is a work around. If you deactivat the LDAP client for groups anything works fine. Simply comment out the last line of your /etc/nsswitch.conf
Now XAMPP should work but now you don't manage your groups by LDAP any more.
But maybe this is helpful for you.