Suggestions for Vaadin version upgradation from 7.1.10 to 7.3.5


We are using vaadin 7.1.10 for our application, and we are planning to upgrade to 7.3.5.
Can anyone tell me the complications if any (sever and client wise) and what is the stable
version in 7.3.5 or 7.3.6 or 7.3.7.
Any kind of suggestions are welcome.
Thank you,

7.3.7 is the latest and the most likely to be stable version. For the other questions have a look at:

Thank you very much quick replay and pointing me to the release note,
I’m looking for the issues if anyone faced by using vaadin 7.3.5.

I’ve just tried upgrading from 7.2.7 to 7.3.8 and faced unpleasant issue: when session expires no notification is shown, but the application just stops to work: can click buttons, tab, selectt different row in table, but nothing happens.