Both on former versions and current ones, (we recently rebuilt from ground up)
get the dreaded 
HTTP ERROR 403 No valid crumb was included in the request

I get this trying to run a job, (so completely blocked atm)
on trying to restart jenkins cleanly, 
loading job confifgurations etc. 

Have logged out and logged in again, 
google search suggests weird stuff like calling some endpoint for a token to make this work