Quick one (i.e. not the prettiest article): I was building another CRM plugin and kept getting a really annoying exception.

System.NullReferenceException: Microsoft Dynamics CRM has experienced an error.

But if I turned on profiling and tried to replay the plugin it would execute as expected. Turing to the CRM server event log I saw this:

ASP.NET event 1309
Exception information: 
    Exception type: NullReferenceException 
    Exception message: Object reference not set to an instance of an object.
   at Microsoft.Crm.Application.InlineEdit.InlineEditJsonConverter.IsLocalizedAttribute(AttributeMetadata attributeMetadata)
   at Microsoft.Crm.Application.InlineEdit.InlineEditJsonConverter.AppendDataValueJson(StringBuilder dataValues, String attributeLogicalName, Entity entity, FormMediator formMediator, Boolean encodeValues, IOrganizationContext context)
   at Microsoft.Crm.Application.InlineEdit.InlineEditJsonConverter.GetEntityAttributeJsonContent(Entity entity, FormMediator formMediator, Boolean encodeValues, IOrganizationContext context)
   at Microsoft.Crm.Application.InlineEdit.InlineEditJsonConverter.<EntityPropertiesToJsonInternal>d__3.MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   at Microsoft.Crm.Application.InlineEdit.InlineEditExtensionMethods.WriteSeparatedValues(TextWriter writer, IEnumerable`1 values, Char separator)
   at Microsoft.Crm.Application.InlineEdit.InlineEditJsonConverter.WriteEntityProperties(TextWriter writer, Entity entity, FormMediator formMediator, NotificationCollection notifications, PrivilegeCheck privilegeChecks, Boolean appendEntriesForFirstTimeLoad, Dictionary`2 parameters, Boolean encodeValues)
   at Microsoft.Crm.Application.InlineEdit.ReadFormDataBuilder.WriteFormDataJson(TextWriter writer)
   at Microsoft.Crm.Application.InlineEdit.ReadFormDataBuilder.WriteFormattedEntityData(TextWriter writer, Boolean isTurboForm)
   at Microsoft.Crm.Application.Pages.Form.FormDataPage.Render(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

I figured I was sending data that couldn’t be rendered. After going back and forth trying to debug I noticed that my attribute keys had a capital letter in the middle (i.e. “contoso_entity_customBlah”). That’s was an hour of my life because of a capital letter.

p.s. I noticed that sometimes when debugging the profiler would throw an uncatchable exception, but only if a debugger was attached. The debugger couldn’t detach once the exception was thrown.

I’d replay the plugin: no exception.

Attach the debugger and replay: see a caught exception! Then the plugin tool would crash due to an uncaught win32 exception. Of course I couldn’t debug the plugin tool because I already had a debugger attached, and I couldn’t detach the debugger because yadda yadda yadda. Turns out if you try to debug a sandboxed plugin in some circumstances the debugger in traceinternal tries to get fileiopermission and fails (because sandbox). So yeah, it was the debugger throwing an exception that it didn’t catch.

I ended up attaching the debugger, hitting a breakpoint, detaching the debugger, then reattaching the debugger after the plugin tool threw an exception. Of course the solution was to debug outside the sandbox.