You may have turned on password protection without first setting a password. Try entering 0000 using the remote control.
If you have entered an incorrect password too many times and see a message displaying a request code, write down the code and contact Epson. When you contact EPSON support, provide the displayed request code and proof of ownership for assistance in unlocking the projector.
If you lose the remote control you cannot enter a password. Order a new one from Epson.