Hi Michael,

Thanks for the suggestion, I'll keep it in mind if I find errors again and i willreport them to OT.

Also error_log is very useful, I'll try it with other components.

I edited the line and now it works fine.

This post can be helpful if anyone upgraded and found some warnings.

As a first step I would temporarely log $code and $file like

function ossn_register_language($code = '', $file) {
error_log('CODE ' . $code . ' FILE ' . $file);
        if(isset($code) && isset($file)) {
                global $Ossn;
                $Ossn->locale[$code][] = $file;
        }
}

Of course this would give even more lines in your log file,
but hopefully you'll know afterwards WHEN the warning occurs and pass it to Openteknik

Next, I'd change the code like

function ossn_register_language($code, $file) {
        if(isset($code) && isset($file)) {
                global $Ossn;
                $Ossn->locale[$code][] = $file;
        }
}