Getting Error -26612: HTTP Status-Code=500 (Internal Server Error)

Hi,
We have a website which we decided to test using load runner. We started loadrunner, access the site then opened a page just enter the data, save it, then logout from the application. We then stopped recording in load runner.
We cleared the data in the database.
We then ran the script in loadrunner but we are getting the following error
Action.c(109): Error -26612: HTTP Status-Code=500 (Internal Server Error) for "http://mysite/aaa/UI/group_Add.aspx?PageNo=0&PageSize=10"
We are using the following softwares
Load runner - 9.0
The site is hosted in a Windows 2003 server with 1 GB RAM
The application was developed using Visual Studio 2005 and SQL Server 2005.

can anyone help us in finding a solution to this error.

Thanks in advance
Venki