You should never get a HTTP 500 error in normal operation mode. There are two causes for HTTP 500 errors:
A major problem on our side.
A problem with your request.
The first thing you should do is examine possible problems with your request:
Missing Required Parameters.
All parameters with a non-string data type are required. This include numerics, dates, booleans, and enumerations (which are really numerics). Only missing string values will not cause an HTTP 500 error.
Enumerations are case-sensitive. Make sure you look at the list of valid values in the SOAP, GET or POST description. Our test form makes it easy by using drop-downs but your code must be correct.
For instance, you may get the following response if you omit an integer parameter:
System.ArgumentException: Cannot convert to System.Int32.
If your request is valid and the problem persists, there might be a problem on our side so email us