Answer:
The Overload detected message can be displayed if the maximum load is set too low or to zero in 'preferences'
Also Emperor will protect the system by setting the maximum load to that of the ILC connected at the time of program creation.
If the ILC is switched to a higher capacity without loading a new program the maximum load will remain at the previous ILC's value which then could be too low for the test being run.
It may also be a true overload of the ILC which cannot be cleared and will not allow any further testing and the ILC will need returning to Mecmesin for Investigation.