If you have two duplicated contacts, A and B, and contact B has an associated event registration. When you try to merge the two contacts and make A the master, the merge fails with the message "We can't process your submission because it includes new values for one or more read-only fields."

The trace log shows some more details:

ErrorCode: 0x80040265
Message: We can't process your submission because it includes new values for one or more read-only fields.;
[Microsoft.Dynamics.EventManagement.CrmPlugins.EventMgmtPlugin: Microsoft.Dynamics.EventManagement.CrmPlugins.EventMgmtPlugin.Plugins.PreventModificationsOfReadOnlyFieldsPlugin]
[fe57a9f6-98a7-e911-b823-00155dc24900: Microsoft.Dynamics.EventManagement.CrmPlugins.EventMgmtPlugin.Plugins.PreventModificationsOfReadOnlyFieldsPlugin: Update of msevtmgt_eventregistration]

2019-11-19T16:36:44.5129350Z :: PreventModificationsOfReadOnlyFieldsStrategy for 0
2019-11-19T16:36:44.5129350Z :: This action is restricted. At least one field that is being modified is marked as 'read-only' and therefore is not allowed to update the entity.
2019-11-19T16:36:44.5129350Z :: Begin: GetLocalizedMessage, messageCode: ReadOnlyFieldsCannotBeModified
2019-11-19T16:36:44.5285575Z :: User language is: 1033
2019-11-19T16:36:44.5285575Z :: Begin: RetrieveJsonWebResourceByName, l...).

The plugin should ideally cope with the situation where the contact field is being updated due to a merge happening and allow the field to be updated, as otherwise there is no way to merge these duplicated records.
Needs Votes



We did reach out to support on this matter and the answered that we should always disable the plugin:

I really don't think that any basic D365 will be able to do this so they will always have to reach out to their partner or Microsoft support. So please make this merge function available or at least let us know what are the fields that the plugin checks as even manual change of event registration is blocked by the same plugin.

Category: Event Planning and Management