Forum Discussion
Expression.Error: We cannot apply operator & to types Number and Record
I started getting this same error, too.
I did some on-demand refreshes a few minutes apart for a simple dataflow. The failures appear random, but all have the same error (listed at the bottom).
The tables listed above are a duplicate and reference of a table that pushes to a lakehouse. I wasn't sure if the dataflow failed because the tables were reference tables vs duplicate tables so i created both types to test. But, it doesn't matter. As the screen shots show, either or both can fail randomly.
When I disable staging on these tables, the dataflow refreshes successfully. However, that means I can't use Get data > Dataflows to select these tables, defeating the purpose of "Enable staging".
This dataflow refreshed without errors previously. Is something broken behind the scenes or am I doing something wrong ?
Error Code: Mashup Exception Expression Error, Error Details: Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Failed to insert a table., InnerException: We cannot apply operator & to types Number and Record., Underlying error: We cannot apply operator & to types Number and Record. Details: Reason = Expression.Error;Message = We cannot apply operator & to types Number and Record.;Detail = [Operator = "&", Left = 2, Right = [...]];Message.Format = We cannot apply operator #{0} to types #{1} and #{2}.;Message.Parameters = {"&", "Number", "Record"};Microsoft.Data.Mashup.Error.Context = System GatewayObjectId: ____ (Request ID: ____).
I also experience this same error and it does appear to be random in nature. My data originates in on premises SQL Server, so I don't think it is related to Postgres as suggested elsewhere.
In fact, the latest instance of this error for me is against my central date dimension table which is created entirely within Fabric from a Power M script.
I do not explictly do what the error message describes, so I believe it is a consequential error from something internal.
I did revisit some of the dataflows (gen2) that were failing and when I explored the destination details, it had the message about some of the data types having changed, but they hadn't.
I'm afraid I have no concrete suggestions other than I have found that revisiting a dataflow and re-confirming the destination details "can" help.
Hi EcurieArgyll. see my post above to this post.
This problem appears to be related to the 2024 April version of the gateway. My team downgraded the gateway to the 2024 February version and that solved the problem. And based on the post I linked to, installing the May version also fixes this problem.