If memory serves, that is the EJ full error. Run the code to reset the electronic journal. I used to remember it but I don't have notes on them now. It will be in the management reports section of your manual. If you need one, one of the users has it here:
https://the-checkout-tech.com/manuals/cashregisters/Samsung_ER-180T_operation_and_programming_manual.html
Registerman, June 2016
