HELP! I'm getting an error about my toolpath not being gcode

Whether I hit delete, stop, or ok that error dialog disappears and I’m left with a dialog saying, “Processing New File, Please wait… Simulating GCode to check for errors…” and this dialog won’t dismiss. I’ve power cycled…didn’t fix it. I’ve hit the emergency stop button and turned it back on. Nothing.

How do I fix this?

Jay