I was setting up a new Child-Parent relationship in the Child-Parent Relationship editor. In the Foreign Key Field dropdown, no entries were appearing. Not knowing exactly what the problem was, I added an index to the foreign key (it did not have one prior to this)When I went back to the Foreign Key Field dropdown, all the fields now appeared from the Business Object
My question is, is it a requirement (even though its obviosuly a very good idea) to have an index set on the Foreign Key Field. Other than this, I dont 'think' I changed anything else