Today we faced issue when we couldn't create Case (incident entity name) with customer set to account which have empty display name. From one side for sure accounts must have display name filled. From another side we don't want to loose any cases. Organization service provided us with no meaningful message:
System.ServiceModel.FaultException`1[Microsoft.Xrm.Sdk.OrganizationServiceFault]: There is no active transaction. This error is usually caused by custom plug-ins that ignore errors from service calls and continue processing.
We've got some plugins and workflows for cases but it doesn't look like anything that bad could happen there. As always enabling trace sheds the light:
>MessageProcessor finish processing message 'Create' for 'post'. >Crm Exception: Message: The display name must contain at least one non-whitespace character., ErrorCode: -2147158364
Disabling ActivityFeeds.Plugins.CaseCreate SDK message processing step in a moment.
There are numbers of complaint regarding ActivityFeeds.Plugins plugins assembly on Dynamics forums.
If you have no idea what is activity feeds or if you customize your CRM greatly, I strongly encourage you to disable any SDK message processing steps that come from ActivityFeeds.Plugins. It will just save you time.