Ok news about this issue :
today i added a gamelist.xml for my kodi roms folder. it worked quite well. After that i noticed that my gb and gbc gamelist.xml were broken. after i reuploaeded those to my pi. the error occured again (white line on top. unresponsive right at startup).
even removing both the gamelist.xml files from gb and gbc wouldt fix the issue. only when i removed the gamelist.xml file for my kodi installation (wich worked prior to the gb and gbc fix) it starts working again
Any ideas how a (even corrupted) xml file can break emulationstation at startup?
I added the xml in question as an attachment since it seems the forum eats my post as soon as i add xml stuff