Naming variables in DAX
There is an existing limitation in the current version of DAX, regarding what names you provide to variables in a DAX expression: a variable name cannot be the name of a table in the data model.
This is not a big issue if you create DAX expressions after importing all the tables you need. However, this can be a serious issue when importing new tables into an existing model. For example, imagine you have created a measure like the following one in a data model. Beware, this is NOT the best approach to compute new customers. We are not interested in performance here, just observe the code: