The type of the source (the value for src-type) contained in the string header is invalid. The only allowed types are:

• 0: none provided
• 1: association handle
• 2: Distinguished name of the sending instance

Normally you should be doing one of two things. If this message is a response, the src-type MUST BE 1 - association handle. If this message is a request, the type should normally be 0. The only time any other value is used is when the request is coming from a specific instance and you need to provide its name for us to resolve an &DN MIB variable.