Error message “Assembly must be registered in isolation” when registering Plugins in Microsoft Dynamics CRM 2011

I had a customer run into the error message “Assembly must be registered in isolation” when trying to register a CRM 2011 plugin. We found this error was being thrown because the user was not a deployment administrator.  If the user is only a System Administrator in the organization, they will be forced to register plugins in the sandbox isolation mode.  After adding the user as a deployment administrator he was able to register the plugin to database without any issues.

In the Security Restrictions section of the following MSDN article it states, “There is a security restriction that enables only privileged users to register plug-ins. For plug-ins that are not registered in isolation, the system user account under which the plug-in is being registered must exist in the Deployment Administrators group of Deployment Manager.“ 

Register and Deploy Plug-ins

Generic Error


Detailed Error


Unhandled Exception: System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]: Action failed for assembly ‘SamplePlugins, Version=, Culture=neutral, PublicKeyToken=829f574d80e89132’: Assembly must be registered in isolation.
Detail: <OrganizationServiceFault xmlns=”” xmlns:i=””>
  <ErrorDetails xmlns:a=”” />
  <Message>Action failed for assembly ‘SamplePlugins, Version=, Culture=neutral, PublicKeyToken=829f574d80e89132’: Assembly must be registered in isolation.</Message>
    <ErrorDetails xmlns:a=”” />
    <Message>Action failed for assembly ‘SamplePlugins, Version=, Culture=neutral, PublicKeyToken=829f574d80e89132’: Assembly must be registered in isolation.</Message>
    <InnerFault i:nil=”true” />
    <TraceText i:nil=”true” />
  <TraceText i:nil=”true” />

Server stack trace:
   at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.Xrm.Sdk.IOrganizationService.Create(Entity entity)
   at Microsoft.Xrm.Sdk.Client.OrganizationServiceProxy.CreateCore(Entity entity)
   at PluginRegistrationTool.RegistrationHelper.RegisterAssembly(CrmOrganization org, String pathToAssembly, CrmPluginAssembly assembly) in C:\Users\jemorl\SDK\CRMSDK 2011\tools\pluginregistration\RegistrationHelper.cs:line 227
   at PluginRegistrationTool.PluginRegistrationForm.btnRegister_Click(Object sender, EventArgs e) in C:\Users\jemorl\SDK\CRMSDK 2011\tools\pluginregistration\PluginRegistrationForm.cs:line 461

Comments (17)

  1. Dimitry Behak says:

    Thank You!

  2. John says:

    Yes thanks.  We were having this issue when importing a solution out of our development system that contained a plugin we wrote.  Adding the user as a deployment admin fixed it!  

  3. Ram says:

    Thanks a lot.

  4. Rikki says:


  5. CrmLearner says:

    Awesome!! It was driving me nuts for a while.

    Thanks a lot.

  6. Avinash says:

    Thanks for the explanation 🙂

  7. Savita M. says:

    I just restarted Microsoft Dynamics CRM Asynchronous Processing Service and again registered the plugin and it worked.

  8. Chaz says:

    Great blog post! Thank you

  9. Alistair says:

    This problem can also occur when you are importing a solution that contains SDK Message Processing steps. The solution is the same; ensure you are signed in as a Deployment Administrator to perform the import.

  10. Tamim says:

    Thanks for sharing

  11. Mahdi says:

    My user added as Deployment Administrator but this error not fixed yet.

  12. krish says:

    Still getting the "Assembly must be registered in isolation”  error even after becoming a deployment adminstrator. I'm using CRM 2013 on-premises and  trying to deploy from VS2012.

  13. Gabriel Dias Junckes says:

    Thanks a lot.

  14. Tumba says:

    Thanks! Saved me from a lot of trouble.

  15. Kobus Vermeulen says:

    Thanks.. Sorted..

  16. Paul says:

    Thank you.