Hi Vikram,

This usually happens when there is a relationship line that is either a) not connected on one or both ends or b) doesn’t have the parent-child columns “associated”.

To verify: on the Database Properties Definition tab for the relationship, select the parent column on the left and the child column on the right and make sure that the button between says “Disconnect”. If it says “Associate”, or there are no parent/child columns, then the relationship is not fully connected.

If you have a lot of relationships, you might try generating a DDL or doing a model error check as that might help you spot the relationship line(s) that are the problem.

The Visio API is a little less than graceful when this happens (and my code doesn’t have complete error handling); I have it on the v2.0 to do list to fix this up some.

Hope that helps,
Scot.