Dataflows and "Complex Columns"

[healthEteam]

So I was all set to build a dataflow this morning.

Got to the dataflow screen, confirmed that my gateway was active and successfully started a dataflow

Datasource is an on prem sql db - a reference to a view.

The columns successfully came into the power query online editor.

I walked through all of the transformations that I needed succsessfully.

After that I got a little yellow triangle warning message that my model couldn't be loaded because I included columns that were of "complex type".

Clicking on the yellow warning icon gave me an option to move forward by omitting the offending columns.

I chose yes and it just returned to the same error.

I did this multiple times thinking maybe I had multiple offending columns and it was omitting one at a time.

No luck.

Is there a resource that would define what would be considered "complex type column" from a sql query? 

Is there are error mechanism within the Power Bi Dataflow setup that would actually tell me what the offending columns actually were.  This may be somewhere but I have yet to find it.

Thanks

[healthEteam · Accepted solution]

So I figured out it was because of power query transform steps that were changing a date/time column to be formatted as time only.  That caused the warning and I assume created the "complex column".  Once I deleted those steps the data flow was finalized and saved.

Now my problem is that when I open Power Bi desktop and try to attach to that dataflow as a source, my credentials that I have used in PBI desktop to sign in with are not the ones being recognized.  It is taking me to my test dataflow that was built on a different O365 tenant space, under completely different credentials.  I tried switching user and then back, still goes to that original dataflow.

[F2]

I have encountered the same issue of "Complex columns not loaded" can you please provide some more help as i am a begginner and i cant get what you meant by power query issue resolved.
Please it's a humble request if you can provide me some sort of more help.
Thanks 

[healthEteam]

Figured that issue out as well by trial and error.

While the credentials you sign in with power bi desktop do not seem to change which tenant space it is looking for the dataflows, the data souce settings icon in the Power Query Editor toolbar will have a datasource listed (Power Bi dataflows) and I had to go in and edit the permissions (credentials) to that datasource directly.  Then the dataflows listing refreshed with the proper tenant space dataflow.

Figured someone else may end up wanting to know that as I havent found this level of instructions available online.