Question Links don't work

Yes, htaccess is renamed.

Everything works with the the 1.5 version of Kunena. ( www.natuurfocus.com/site/forum.html )

The testsite is a exact copy of the live site. Copy made with Akeeba Backup.

Hmmm...

if I understand, you have make acopy of site with K1.5, then you are upgrade K1.5 -> K1.6, enabled SEO and links dont work. Right?

Both site are on the same server?

Try also to change Joomla template and say what heppens. Thank you.

(Back from work)

No, both sites use SEO. The only thing I did was make a copy of the original site and then upgrade kunena to the 1.6 beta 1.

I also changed the theme now to the default JA_Purity theme and the same problem persists.

The 2 website are run on the same server.

On the side:
I also installed a clean Kunena 1.6 beta 1 on another server of the same hosting provider and there works everything.

I would at your place create new copy of original site and go step by step to find in which point all operation is broken. I mean install K1.5 and enable SEO, look if all works well, then update to K1.6 and see if there are some error, If not enable SEO.

The original site has kunena 1.5 installed so I don't have to install that again. SEO also is activated in the original site.

The only thing I did was, copied the original site with Akeeba to the new domain and then installing 1.6 beta 1 over the 1.5 installation.

Hurr1c4n3 wrote: All options set to Yes

I think that's the problem. I've never been able to get everything on my Joomla websites to work properly if I use that third option: Add suffix to URLs = Yes.

See my guide in the Wiki and try those suggestions: Search engine optimization (SEO)