Hi,
If you are receiving a system admin error there should be an error message in your system logs that explains the problem. Please go and check those logs to find the exact problem.
Most likely the problem stems from and attribute that is empty while you are trying to use that object. Thus it is always important to empty check objects that you retrieve before you try to use or change them.
But admin errors stem from actions that error out and there is no error handling to catch the error.