If Statement with Related error message

[kasiaw29]

Hi all, 

I have two tables - table 1 = Sales Contract and table 2 = AFP. 

I have a many to many relationship between them going in both directions. 

I have put data that I want to see in a table and it appears like so and is correct when compared to data from it's original source:

I've created a calculated column as such: 

On Schedule = IF('AFP'[DATE_PAID] <= RELATED('Sales Contract'[PAYMENT REQUIRED DATE]),"YES","NO")

Just want to find out if things are paid on time... but I'm getting the following error:

The column 'Sales Contract Items[PAYMENT REQUIRED DATE]' either doesn't exist or doesn't have a relationship to any table available in the current context.

What seems to be wrong? Does the direction of relationship needs changed? In above table it all look right and returns the right information but I can't seem to use two different dates to compate them to see if things are one time. 

Any help would be madly appreciated. 

Thanks 

[amitchandak]

@kasiaw29 , I doubt it will work in many to many.

You can bring data like this from one table to another

City Name = maxx(FILTER(geography,geography[City Id]=Sales[City Id]),geography[City])

[HotChilli]

"the function follows an existing many-to-one relationship to fetch the value from the specified column"

RELATED won't work on a many to many relationship.

Generally, we don't like many-to-many relationships (they require careful handling) .  So can you re-appraise your model and see if it's correct.