Browser timeout

Hi all!

I have a problem with browser. From time to time all users, who work in T24, are kicked out from the system at the same time. In classic and in desktop such problem never occurs. What would be reason?

p.s. I have noticed that when one user works in the system all is ok, but when few users work the system throws out an error like this

Error message
We have not heard from you for a while. Can you please re-login to confirm your identity?

I have noticed something similar when the jbase_agent dies or is forced to shutdown. You would expect it to just affect your Browser sessions but the Classic sessions also get kicked out.