Did you have a try to reset the Z axis zero positon?

Yes, I did, but its didn’t help.

Do I need to kept plastic protection film on LSD screen, or i need to remove?

Be very careful. On a failed print I did the resin stuck to the base of the vat and the build platform used soo much pressure that it ripped a hole in the vat and the resin leaked over the LCD screen and hardened. Told it can be scrapped off but I tried and it cant come off. 

I reasonably  expect to set up and once running leave it to itself rather than me sit and watch the printer for 5 or so hours. 

The fail occurred somewhere 50 to 150 layers…….had a print of 20mm or so already done. On top of that I am expected to buy a new vat. Guess I need to buy extras as it may happen again any time……