Server was unable to process request.

Question

I have a Webservices written in VB .net.

 

Intermittently I am seeing below issue on one of my servers, when I call the webservices from my client. 

 

System.Web.Services.Protocols.SoapException: System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.NullReferenceException: Object reference not set to an instance of an object. 

The applciation on the server is running without any issue from past 3 years. 

I have the same code deployed on another server aswell, which is running without any issues. 

 

During the issue, I could see the application on the IIS server was in hung state. Untill we manually IIS reset and recycle the applcation pool server will be in hung state, and throwing the same error.

Both the servers are in same configurationa and same pathcing being applied on both the servers.

 

Struggling to find the Root Cause, Could anyone please help me on this?

 

Thanks,

Yash