For anyone else that has this problem - it is most likely caused by having multiple Odoo tabs in your browser logged in as different users. This was my problem anyway.

This will definitely work for you.

Turn the developer mode on.>>>>>Go to Settings>>>>>TEchnical>>>>>System Parameters

Search for Web.base.url. Check this. This should match with the IP you used to run the system. If this doesn't match, your session will get expired.

I solved the problem just replacing "localhost" with 127.0.0.1 (this was in fact the IP presents in "System parameters", thanks DonferaRRi for the hint)

Session ends in approx. 5 minutes. Until today I had no such problems even if I worked logged in for days.

If you suggest me to check the code, can you please provide me instructions how to do that please?

If you dont use any thing in Odoo Session (its idle state),then the session Time out Message is coming after a particular time (based on session time out code,make the changes in the session time out code).Then this issue may solved.

Change your Session expired Time

Solution?

Hello,

Please try refresh page after server restarted.

May be this will help you.

Thanks.

Shamji.

Have you made any changes in code recently ?

Sometimes when changing modules or code in modules it kick me out, but after relog (without server restart) everything works fine.

Clear browser history (temps)

I have this problem on the SaaS online version, and it can happen within seconds. Very frustrating.

Logging out and logging in does not solve it, on the contrary!

Here is an answer from one of the functional consultants.

This error can have 2 origins :

Either you're using 2 devices ( 2 computers or one computer and one smartphone) with your login or 2 persons are sharing your user.

I had an app on my phone. I have removed the account. Let's see what happens.

This seems to have fixed the problem.