Sequential Workflow: The file has been modified by SHAREPOINT\system on

Question

I have a squential workflow that takes Account IDs as plain text from a InfoPath input and converts them into a SPUser field. I can't get the the item to update bc an exception is throw on the Update statement and SystemUpdate.

 CurrentItem["Stakeholders"] = usercollection; //Type: SPFieldUserValueCollection
 workflowProperties.Item.SystemUpdate(false); //Exception here         
 //workflowProperties.Item.Update();  //Exception here


//CurrentItem Definition
private SPListItem CurrentItem
{
     get
     {
         SPList list = workflowProperties.Web.Lists[workflowProperties.ListId];
         SPListItem li = list.GetItemById(workflowProperties.ItemId);
         return li;
      }
}

I've tried checking the item in and out. That doesn't seem to work. I've tried CurrentItem.Item.File.Update(). This does not throw the exception but it doesn't update the item either.

Any help would be much appreciated.

Update

found this in ULS:

Leaving Monitored Scope (EnsureListItemsData#1). Execution Time=16.7994116570681

<nativehr>0x81020015</nativehr><nativestack></nativestack>The file has been modified by SHAREPOINT\system on 03 Mar 2015 12:53:34 -0600.

Possible mismatch between the reported error with code = 0x81070901 and message: "The file has been modified by SHAREPOINT\system on 03 Mar 2015 12:49:15 -0600." and the returned error with code 0x81020037.

Answer 1

Okay I found the issue. Typical dumb mistake from staring at this too long...

CurrentItem["Stakeholders"] = usercollection;                
CurrentItem.Update(); //NOT workflowProperties.Item.Update();

Problem is now the value isn't setting but that's a separate issue. Hopefully this helps someone.