You attempt to Build your Analysis Services solution but get a “object reference not set to an instance of an object” error when you try the Build function. This can be any number of things but as a guide you can try checking the following within your SSAS solution :
DSV – Check the DSV and make sure each object returns data without error.
Dimensions – Check each and every dimension in the solution by manually opening and checking for errors. Alternatively install BIDS helper and activate the Dimension Health Check on each.
Measures – Check the aggregation property and ensure the Aggregation function is correct. For example if you don’t have a Date Dimension in your solution but have selected Last Non Empty, this will trigger the object reference not set to an instance of an object error.
Note – Restarting Visual Studio is unlikely to resolve.
Happy error hunting.