How can I reply to a get request from managing software such as (solarwinds)

I use sharpSnmp to make a SNMP agent (virtual SNMP machine) that communicates with monitoring software. But my agent is not detected by Monitoring apps. I can get the Message from monitoring software by this code, the incoming message from monitoring software (solarwinds) has an OID: "

Can't compile c# project because of some tuple error when referencing an external dll

I have an error, when I try to build my .net 4, c# project. Everything works great, but when I add an external reference to a given DLL, it stops working, it can't build, throws this type of some errors: Error 36 The type 'System.Tuple' exists in both 'C:\Program Files\Reference Assemblies\Microsoft...