Error message "Unable to load plug-in type"


  • Hi I used plugin registration tool and updated an existing plugin by a new dll.. and then afer that I started recieveing error messages on the CRM on our Dev environment. Error message "Unable to load plug-in type" it was registered for contact entity for post create and update but we are getting this error on any entity updates and creates..

    Any help on how to resolve this issue with be deeply appreciated.

    thanks in advance,

    Future MVP

    • Edited by Future MVP Wednesday, December 15, 2010 12:06 AM Signature Change
    Wednesday, December 15, 2010 12:03 AM


All replies

  • Try enabling tracing on the CRM Server and interrogate the resultant trace files for additional error information.

    --pogo (pat)
    Wednesday, December 15, 2010 12:49 AM
  • have you register this as Disk or database?

    if you register this as disk then make sure DLL exist on Server\assmbely folder on Server and also make sure you registered the assembly from the servce onlt..

    Also make sure restart CRM website (i.e. iisreset) and restart MS Asyc. Service after registrung the assembly and steps in plug in registration tool..

    and see if this helps..

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    Wednesday, December 15, 2010 12:07 PM
  • Hey Mayank, thanks for the reply .. I actually did register it to database...
    Wednesday, December 15, 2010 2:37 PM
  • okay, does it working now then?
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    • Marked as answer by Future MVP Wednesday, December 15, 2010 2:56 PM
    • Unmarked as answer by Future MVP Wednesday, December 15, 2010 2:57 PM
    Wednesday, December 15, 2010 2:41 PM
  • Nope I am still getting that error , we adctually did restart the services and did the IISReset and we even rebooted the SQLServer..  no luck

     any entities that are calling this plugin throws that error.. and the other pulgins work fine whihc doesnt make a call to this dll...

    Wednesday, December 15, 2010 2:58 PM
  • Does the plugin assembly reference any other custom assemblies ? If so, they'll need to be registered in the GAC
    Microsoft CRM MVP -
    Wednesday, December 15, 2010 7:03 PM
  • Is assembly signed or not?   Please go through checklist from following link to see if you missing any step in plug in applcation..

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    Wednesday, December 15, 2010 10:58 PM
  • Hi,

    Are you on a x64 bits environment?

    If so, try to compile your plugin dll and dependencies explicitly in for x64 bits. I had the same problem some days ago.

    If x86, viceversa. Try the same.

    Also, make sure you run an iisreset aftertwards.

    Hope this help,


    Microsoft MVP Dynamics CRM | My Twitter: | My blog:
    Thursday, December 16, 2010 11:22 AM
  • While this thread is 3 years old, yet I just encountered the same problem about half an hour ago, and I believe this is a bug within CRM Solution Import routine.

    What I had was a plugin which was imported previously. Then, I added new plugin steps and got 'Unable to load plugin type' when registering the new plugin steps I added.

    The solution I have is:
    a. Import just the plugin assembly without the new plugin steps, and publish.
    b. The plugin assembly is now updated with the new plugin class definition. Then add the new plugin steps and import the solution again.
    c. The solution should now be imported successfully.

    What I believe the bug is CRM Solution Import routine checks for the plugin class/type definition in the existing plugin assembly in the server rather than the new plugin assembly in the solution being imported.

    By the way, all solutions are unmanaged. Perhaps, the same bug will not happen in Managed solution.

    HTH anyone else experiencing the same issue.


    Saturday, November 30, 2013 1:19 AM
  • Hi Henri,

    I too faced the same issue while updating the plug-in.

    I followed the same steps given by you. It worked like gem. Thanks a lot :)


    M. Prasad Reddy.

    Monday, April 27, 2015 3:13 AM
  • I can confirm this is still an issue with CRM 2016. The steps we followed to resolve are a little different as stated above by Henry_L: 1. Remove the plugin steps and Plugin Assembly from the Target environment 2. Import solution containing new plugin steps and Plugin Assembly to Target environment This helps remove the middle steps of re-importing a solution twice.f
    • Proposed as answer by KD_Mike Tuesday, May 17, 2016 8:25 PM
    Tuesday, May 17, 2016 8:24 PM
  • Hi 

    I am trying to import an Managed solution into Vanilla environment in CRM online 2016 but still it says unable to load plugin assembly.



    Wednesday, June 01, 2016 2:35 PM