I think I kind of solved it, by salvaging stuff from this thread:
https://xoops.org/modules/newbb/viewtopic.php?topic_id=57404&forum=28&post_id=253680#forumpost253680
I guess my PHP is 5.2, maybe thats why.
But now with another site that i am trying to fix (same problem), i am getting this:
Fatal error: Call to undefined function xoops_gethandler() in /home/marjanmc/public_html/navtravels.com/include/common.php on line 92
I tried to recopy common.php, ..etc.., but i dunno wut the problem is, i removed the xlanguage "api" statement from common.php, useless.
Please advice.