The getting started guide
here for the Jaguars tells you what the error codes mean. From that document, a slow flashing red light means one of the following:
- Power supply under-voltage
- Over temperature
- Over current
- Limit switch activated in the current direction of motion
I would start by checking the two limit switch jumpers are in place - that's probably the most common problem. If that's not the issue, disconnect your output leads to ensure nothing is shorted. Check the input leads to ensure you have sufficient voltage. Since it's when you start up the robot, I'm doubting it's a temperature issue.