Error: Column '' in Table '' contains blank values and this is not allowed

[Anonymous]

On refreshing my data this morning, I get an error: Column '' in Table '' contains blank values and this is not allowed for columns on the one side of a many-to-one relationship or for columns that are used as the primary key of a table.

I have two tables: a list of unique IDs ('Unique') and a large table with many IDs ('Report) which have a valid one to many relationship. I have confirmed that there's no blank IDs in either table and the error occurs when trying to create a new table by doing =NATURALLEFTOUTERJOIN('Unique','Report')

Is nullable is set to false for the IDs on 'Report' and this has been working perfectly for a week now and I can't understand why it would suddenly break. Any suggestions would be greatly appreciated. 

[amitchandak]

@Anonymous , Check if one of the tables is getting a new value as blank.

Also, check any issues report on Oct -21 release. In case you are on that release

https://community.powerbi.com/t5/Issues/idb-p/Issues