Sitecore 7.5 logs TypeLoadExceptionHolder cannot be converted to type Sitecore.Analytics.Model.Framework.IFacet

Question

I am having the following error in the Sitecore 7.5 logs. Any idea why we are getting this error?.

9660 13:14:42 INFO HttpModule is being initialized Heartbeat 13:15:26 ERROR Exception in alarm clock event subscriber. Exception: System.ArgumentException Message: Object of type 'System.Runtime.Serialization.TypeLoadExceptionHolder' cannot be converted to type 'Sitecore.Analytics.Model.Framework.IFacet'. Source: mscorlib at System.RuntimeType.TryChangeType(Object value, Binder binder, CultureInfo culture, Boolean needsSpecialCast) at System.Reflection.RtFieldInfo.UnsafeSetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, CultureInfo culture) at System.Runtime.Serialization.ObjectManager.DoValueTypeFixup(FieldInfo memberToFix, ObjectHolder holder, Object value) at System.Runtime.Serialization.ObjectManager.CompleteObject(ObjectHolder holder, Boolean bObjectFullyComplete) at System.Runtime.Serialization.ObjectManager.DoNewlyRegisteredObjectFixups(ObjectHolder holder) at System.Runtime.Serialization.ObjectManager.RegisterObject(Object obj, Int64 objectID, SerializationInfo info, Int64 idOfContainingObj, MemberInfo member, Int32[] arrayIndex) at System.Runtime.Serialization.Formatters.Binary.ObjectReader.RegisterObject(Object obj, ParseRecord pr, ParseRecord objectPr, Boolean bIsString) at System.Runtime.Serialization.Formatters.Binary.ObjectReader.ParseObjectEnd(ParseRecord pr) at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run() at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage) at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage) at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, IMethodCallMessage methodCallMessage) at Sitecore.Analytics.Data.DataAccess.SubmitQueue.FileSubmitQueue.Dequeue() at Sitecore.Analytics.SubmitQueueService.WakeUp() at Sitecore.Services.AlarmClock.Heartbeat_Beat(Object sender, EventArgs e)

Answer 1

It looks like there is somethings with the Submit Queue.

Take a look at the "Submit Queue" folder in the Sitecore "Datafolder" directory. Remove the wrong files and check the file permissions.

Answer 2

In my case (i am running Sitecore 9) the facet types also changed and some of the old facet objects remained serialized on disk in ~\Website\App_Data\Submit Queue folder. After deleting the file in that folder the problem is fixed. The reason why Sitecore stores facet objects there is that if the xConnect is not available for whatever reason the current session gets serialized (including contacts info and facets) and is written into ~\Website\App_Data\Submit Queue folder. Sitecore then retries sending this session data to xConnect at certain intervals.