it may be a mootools incompatibility in this version of Joomla.
let me take a look.

if you want, you can give me access to your site so I can take a look right there.
our email is joomlafinances@gmail.com

Uhmm forgot to mention, i have the issue's in the backend of joomla.
so there are no mootools incompatibility there.

When i want to create a new J!invoice contact and want to link that to a excising joomla user then i have already the issue that i can't search to the user.

Before I grand u access i want to ask u if you can reproduce on your side.
I have a company running on this website...

yes I can reproduce it on my side but will take me a few hours because I'm not at the office right now, and I have to build a new test environment to see it (that's why I asked you for access, to look at it quickly, but I understand your point).

the backend incompatibility can be related to MooTools as well. the user search function (on Contacts area) is an AJAX based function, which uses MooTools functions, so that could be it. Maybe the version of Mootools for 2.5.4 is not the same as 2.5.6...

Ok if you can test it on your side first please, if not i will grand u access.

you can mail me on the know mail adress

Tnx in advantage

hello!

ok, so I installed 2.5.6 on my local test server, also upgraded the old one.. and cannot get the problem you are getting. the link users still work fine on my end in Joomla 2.5.6! so probably it is something specific in your site...

maybe the best way to go would have access to your site... I won't change anything, I will only look for JavaScript errors.

Germi

I have send u a mail with the username and password