I was piloting my Railjack as a 'space child' and randomly stopped being able to do any of my abilities. ie boost, drift, open the Tactical map or even use transference to get back to my Warframe, I was also unable to exit the Railjack.
This has happened to me in the past and from what I can tell it seams to be caused by the Warframe avatar being deleted, as both time the Railjack was being invaded and when I got out of the pilot seat my Warframe was not where I left it or anywhere else on the Railjack.
I started the season by joining my friend's Railjack mission, returning to dry dock, disbanding the squad and reforming with me as host, we then started and completed a Railjack mission, returned to the dry dock, made some changes to my Railjack, then started a new mission in which this issue occurred.
I have backed up my EE.logs if needed.