title: SharePoint 2013 Event Receiver Error
body: <p>I have the following SharePoint 2013 list event receiver. When the receiver runs on item updating it throws a error. The error below is from the SharePoint ULS logs. Has anyone encountered this before, and/or know how to resolve it?</p>
  
  <p>Code:</p>
  
  <pre><code>    public override void ItemUpdating(SPItemEventProperties properties)
      {
          try
          {
              base.ItemUpdating(properties);
  
              properties.Status = SPEventReceiverStatus.CancelWithError;
              properties.ErrorMessage = "You cannot updated a approved requisition";
          }
          catch (Exception ex)
          {
              properties.Status = SPEventReceiverStatus.CancelWithError;
              properties.ErrorMessage = ex.Message.ToString() + " Stack Trace -" 
                   + ex.StackTrace + "Inner Exception -" + ex.InnerException;
          }
      }
  </code></pre>
  
  <p>Error:</p>
  
  <ul>
  <li>UserCodeExecutionProxy call failed. Microsoft.SharePoint.UserCode.SPUserCodeExecutionPipelineFailedException: Unable to load assembly group. The user assembly group provider threw an exception while trying to provide user assemblies for the specified assembly group. ---> Microsoft.SharePoint.SPException: Cannot complete this action.  Please try again. ---> System.Runtime.InteropServices.COMException: Cannot complete this action.  Please try again.0x80004005     </li>
  </ul>
  
  <p>at Microsoft.SharePoint.Library.SPRequestInternalClass.GetFileAsStream(String bstrUrl, String bstrWebRelativeUrl, Boolean bHonorLevel, Byte iLevel, OpenBinaryFlags grfob, String bstrEtagNotMatch, Object punkSPFileMgr, Boolean bHonorCustomIrm, IrmProtectionParams fileIrmSettings, String&amp; pEtagNew, String&amp; pContentTagNew, SPFileInfo&amp; pFileProps)     </p>
  
  <p>at Microsoft.SharePoint.Library.SPRequest.GetFileAsStream(String bstrUrl, String bstrWebRelativeUrl, Boolean bHonorLevel, Byte iLevel, OpenBinaryFlags grfob, String bstrEtagNotMatch, Object punkSPFileMgr, Boolean bHonorCustomIrm, IrmProtectionParams fileIrmSettings, String&amp; pEtagNew, String&amp; pContentTagNew, SPFileInfo&amp; pFileProps)     --- End of inner exception stack trace ---     </p>
  
  <p>at Microsoft.SharePoint.SPGlobal.HandleComException(COMException comEx)     </p>
  
  <p>at Microsoft.SharePoint.Library.SPRequest.GetFileAsStream(String bstrUrl, String bstrWebRelativeUrl, Boolean bHonorLevel, Byte iLevel, OpenBinaryFlags grfob, String bstrEtagNotMatch, Object punkSPFileMgr, Boolean bHonorCustomIrm, IrmProtectionParams fileIrmSettings, String&amp; pEtagNew, String&amp; pContentTagNew, SPFileInfo&amp; pFileProps)     </p>
  
  <p>at Microsoft.SharePoint.SPFile.GetFileStream(SPWeb web, String fileUrl, Boolean honorLevel, SPFileLevel level, OpenBinaryFlags openOptions, String etagNotMatch, SPFileStreamManager spMgr, SPFileRightsManagementSettings rightsManagementSettings, String&amp; etagNew, String&amp; contentTagNew, SPFileInfo&amp; fileprops)     </p>
  
  <p>at Microsoft.SharePoint.SPFile.OpenBinary(SPOpenBinaryOptions openOptions)     </p>
  
  <p>at Microsoft.SharePoint.Administration.SPSolutionLanguagePack.GetSolutionInfoFromGallery(Guid siteId, Guid solutionId, String solutionHash, String&amp; fileName, String&amp; hash, Byte[]&amp; fileBytes)     </p>
  
  <p>at Microsoft.SharePoint.Administration.SPSolutionLanguagePack.CreateSolutionPackage(SPRequest request, Guid siteId, Guid solutionId, String solutionHash)     </p>
  
  <p>at Microsoft.SharePoint.UserCode.
  SPUserCodeLightweightSolutionAssemblyGroupProvider.GetAssembliesInGroup(Guid siteId, String assemblyGroupId)</p>
  
  <p>at Microsoft.SharePoint.UserCode.SPUserCodeAssemblyCacheManager.EnsureUserCodeAssemblyGroupIsCached(Guid siteId, SPUserCodeAssemblyGroupId userCodeAssemblyGroupId)     --- End of inner exception stack trace ---    Server stack trace:      </p>
  
  <p>at Microsoft.SharePoint.UserCode.SPUserCodeAssemblyCacheManager.EnsureUserCodeAssemblyGroupIsCached(Guid siteId, SPUserCodeAssemblyGroupId userCodeAssemblyGroupId)     </p>
  
  <p>at Microsoft.SharePoint.UserCode.SPUserCodeExecutionHost.Execute(Type userCodeWrapperType, Guid siteCollectionId, SPUserToken userToken, String affinity, SPUserCodeExecutionContext executionContext)     </p>
  
  <p>at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]&amp; outArgs)     </p>
  
  <p>at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)    Exception rethrown </p>
  
  <p>at [0]:      </p>
  
  <p>at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)     </p>
  
  <p>at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData&amp; msgData, Int32 type)     </p>
  
  <p>at Microsoft.SharePoint.Administration.ISPUserCodeExecutionHostProxy.Execute(Type userCodeWrapperType, Guid siteCollectionId, SPUserToken userToken, String affinityBucketName, SPUserCodeExecutionContext executionContext)     </p>
  
  <p>at Microsoft.SharePoint.UserCode.SPUserCodeExecutionManager.Execute(Type userCodeWrapperType, SPSite site, SPUserCodeExecutionContext executionContext)</p>