Check the code runs management, often appear alarm codes 404 and 500 when the alarm fault, then those are the police do?
404 is the front alarm code is wrong, if the alarm 404 when you run the code, then go to the front desk to find Web pages mistake.
500 alarm is the background code is wrong, if the alarm 500 when you run the code, then go look for background processing aspx page or pages ashx mistake.