Many to many relationship identified in error

[CloudMonkey]

Hi,

I have a test file (please see the url below) with 2 tables, each with 1 column. When I try to join them I get warned it's a many to many relationship which is incorrect. I've checked the table called "Categories" has no duplicates or nulls. Please can you tell me why it's identifying a many:many relationship?

https://filebin.net/may4tw69egrax0fk

Many thanks,

CM

[Anonymous]

Can you share a screenshot? Somehow I can't open that link

[HotChilli]

Yes, there are duplicates.

Identify them by dragging column1 of Categories on to a table visual twice.  Make one of them 'Count' in the Values well.

Sort the table by that column to show the categories with 2.