Hi are you saying when you power up the mount the HC says "Starsense ready press Align" etc. to begin alignment then the error appears when you start the SS alignment? Or does the HC display the "Err camera status" message straight away upon powering up?
If it's the first option then it sounds like the Starsense camera is being picked up at least to start with, with the second option the HC displays the error message and you are locked out of doing anything else.
As you said Starsense was at one time working, I would say this is a cabling problem.
I only once had this error and removing and reconnecting the cables quickly cured it, carefully check the cables and contacts it does not take much to make a bad contact. Also it would not do any harm to do a camera reset, I would also only use the HC until you find the problem.