I registered one plugin assembly with two plugins written targeted to contact entity and registered in one of Dynamics CRM 2015 Online instances. It worked properly after adding steps into it. Here I am discussing the issue raised, an observation was done and the solution to the issue. But this only on a scenario for this issue to be raised and there can be many other scenarios to see this same issue.
Issue: After some time I wanted to add few more plug-ins to the same assembly, targeting some custom entity events and I updated the same registered plugin assembly with the newly build assembly. However, after adding steps to the relevant plugins and after triggering relevant events I got some errors from all the plugins I newly added. I checked the very first plugin events I registered in the same assembly and those functioned perfectly.
Error Message: All the errors showed the same error message “The plug-in type could not be found in the plug-in assembly:” in them.
Unhandled Exception: System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=184.108.40.206, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]: System.ArgumentNullException: Value cannot be null. Parameter name: TrackingId: 87e5f936-7499-4bc1-b649-f78fd4739016, Depth: 1, Message: SandboxAppDomainHelper.Execute: The plug-in type could not be found in the plug-in assembly: Continue reading "ISSUE: The plug-in type could not be found in the plug-in assembly"