I have a web application written in ASP.Net 1.1 which uses a standard web service.

The web service uses a COM dll to process requests and return results to each individual web client. The actual processing done by the dll is not important here, but the web service needs to create a new instance of the dll for each web client. This is ok as the application is run on a local Intranet and does not have a large number of users.

This mechanism works fine most of the time. However, occasionally it gives a SoapException error with the message "Server was unable to process request. --> The server thew an exception" appearing in the web browser. "Exception details: System.Web.Services.Protocols.SoapException Server was unable to process request. --> The server thew an exception". The stack trace mentions calls to SoapHttpClientProtocol.ReadResponse() and SoapHttpClientProtocol.Invoke().

Once this error has occurred, IIS needs to be restarted before the application will work again.

Has anyone come across this problem before?

Thanks for your help.