Hi Anke Thank you very much! You wrote:

our config still works well - see screenshot.

We have exactly the same configuration - but when trying to access we are getting the following error message: Proxy Error The proxy server received an invalid response from an upstream server. The proxy server could not handle the request Reason: Error reading from remote server I tested the same configuration on my demo installation https://koha.adminkuhn.ch - there it works well. The demo installation is directly in the internet with no (outgoing) firewalls involved.

Changing 80 to 443 doesn't help - the SRU search doesn't work anymore with that setting.

Changing 80 to 443 didn't help either on my demo installation. Thus I think this is a problem of the local firewall of our library that doesn't like the redirect from port 80 to 443. It will have to be solved locally. Best wishes: Michael -- Geschäftsführer · Diplombibliothekar BBS, Informatiker eidg. Fachausweis Admin Kuhn GmbH · Pappelstrasse 20 · 4123 Allschwil · Schweiz T 0041 (0)61 261 55 61 · E mik@adminkuhn.ch · W www.adminkuhn.ch