This error occurs when action is not specified for a system event.
Specify the required action for the system event.
Example
[System: Events]
On: Load Company:
In the above example, there is no action specified for the system event On: Load Company, Hence the message error T0033: No action specified for system event.
The code is corrected by adding an action to the system event On: Load Company .
[System: Events]
On: Load Company:Yes:Display:Balance Sheet