Unable to communicate with server. Saving is not possible at the moment.

[ADA]

What is the error or where can I find the error log if Confluence displays the error message "Unable to communicate with server. Saving is not possible at the moment." at create/edit page? 

I cannot see any error at all in following log files:

• confluence-stderr[...].log
• catalina[...].log
• atlassian-confluence.log

Some facts:

• This happens very randomly for all accounts/users
• No firewall between
• No specific time or date 
• all users are orchestrated by an internal Active Directory

So where should I start to look? 

Confluence version: 6.0

[Marcel Woschek]

There is already a question facing this problem: here

Maybe you can already find a solution there.

It would also be benefical if you would share your problem on this question so the progress is collected in one question only