Error messages in MDX SELECT statements and what they mean

Anyone that has tried to learn MDX will know that, when you make a mistake somewhere in your code, the error messages that Analysis Services gives you are pretty unhelpful. It was suggested to me recently while I was teaching an MDX course that I should blog about common error messages and what they actually mean; so here’s a list of a few example queries using Adventure Works that return confusing errors, the error messages themselves, and details on how to solve the problems. I’ve deliberately concentrated on query-related errors rather than calculation-related errors (that can be a future blog post); if you can think of any more errors that I should cover please leave a comment.