After the move it came out that some pages didn't work as expected i.e. some redirections were failing. The redirections were implemented using header function e.g.
When I checked the php logs I found common error "Headers already sent". Don't want to explain here what does it mean - there's plenty of answers here ;) The only thing that made me wonder was why it was working on the old server. When I compared the php.ini files from both servers I found out that the new one was configured not to useoutput buffering. The temporary fix was enabling this by setting in php.ini:
This is not the cleanest solution and may affect application's performance but works immediately. The long-term solution is to ensure that your app is not sending any output before calling the