odata not loading

Finally got there (once again thanks to fiddler :mantongue:).  Used Fiddler Web Debugger to monitor, copy and manipulate and resubmit requests.  I can confirm having done this that my initial suspicions were correct.  If your column names, including a comma(,) in between each (eg. column1,column2,column3) exceed 2048 characters you will receive a 404 Not Found error in Power BI (or Power Query - it's the same in both Excel and Power BI Desktop).

Now this is not a Power BI issue.  The Dynamics CRM OData feed only allows for 2048 characters to be passed to the service.  Anything more is essentially a bad request (eg it doesn't exist!).  See the definition here https://msdn.microsoft.com/en-us/library/gg309461.aspx  I naviely thought the PBI Team had somehow negated the 2048 character limit, but it's for all HTTP requests which is obvious post testing and confirming :robotembarrassed:

Be aware that when you use functions such as Keep Errors or Remove Errors (which are the 2 most important that I've found), the OData request includes all columns.  I think this is a potential bug in Power Query which I'll submit to the support team.  I would have thought only the columns left in your query would be included in the $select= filter for the OData request? it of course may not be this simple to resolve......

I have just tried this with the split function which also returns an error to so actually this is looking like a pretty fundamental issue to be honest...