Use a redirecting authentication (form if RUNTIME-598 is not corrected or CAS)
Connect to the cms
Play
Shut the server down and restart it in a row
Play

NPE in js because, a xml request is redirected to a html form
Should not do a NPE but should return null ; and open an error message telling the user should re-authenticate : we could even open a small popup with a dedicated url to authenticate and close in a row : but the main appli may be in a unstable state

(check if modification of DirectComm is also needed)