Error while deploying cube "Object reference not set to an instant of an object"

If you are doing some structural changes to your multi-dimensional cube database and while deployment if you receive an error saying "Object reference not set to an instant of an object" then its really hard to find which reference is missing or what exactly error wants to say. So today we are going to discuss about this error. Generally this error appears while cube deployment like the following one.

So if you receive error like this then simply go to "Dimension Usage" tab and check whether all the required dimension relationships are in place or not and if not then you might see like;

Just set the appropriate relationship wherever they are missing and deploy cube. This will resolve your issue.