Urgent: External registration stopt working

Hi There,

Suddenly it was not possible anymore to register a sub site.

Instead of http://subdomain.domain.com WordPress is creating http://subdomain.http://domain.com?!

If I create a new site from the dashboard, everything works well.

I did update some plugins since the last registration went well, but I can’t remember which one it was.

Before I deactivate all plugins I wonder if anyone here as an idea what could cause the problem?

Many Thanks in advance!