Hello everyone,

This blog post is on issue related to Unified Service Desk. We were getting an error whenever we create a Hosted Control in any of the organization in our Dev server. This started happening all of a sudden.

Error:

[Microsoft.Uii.Customization.Plugin: Microsoft.Uii.Customization.Plugin.RestrictDataDuplicationPlugin]
[923014f5-390e-42be-95e4-17d6f90ff805: Microsoft.Uii.Customization.Plugin.RestrictDataDuplicationPlugin: Create of uii_hostedapplication]

Following is one useful article provided some insights into possible causes but it didn’t help us to fix the issue. However, we were confident that issue is around sandbox service.

https://community.dynamics.com/crm/b/crminthefield/archive/2013/01/29/the-plug-in-execution-failed-because-no-sandbox-hosts-are-currently-available

So, we restarted our sandbox and app servers which has fixed the issue in all except one organization. Then this question popped up “Why we need sandbox mode for Microsoft provided plugin in onprem environment?”. Answer – “Not Required..!!”. We then changed following UII and USD assembly isolation mode to “None”.

Plugin assemblies:

Microsoft.Uii.Customization.Plugin
Microsoft.Crm.UnifiedServiceDesk.Plugin

This solved our issue and we were able to create hosted controls in all of our orgs.  This may not be an actual fix for the root cause but a simple workaround for the issue(Remember it’s only for onprem).

Hope it helps..!!