mt5 strategy tester - connection closed


Hi, today when I opened mt5 strategy tester I am getting an error, while it was working fine when I turned off my pc last night. When trying to backtest I get the message "connection closed" on core 1. I have tried to install a new mt5 terminal but I get the same error message. Does anyone know what is causing this and how to solve it?

Carl Schreiber  
Please provide sufficient information about your settings and the log entries...