One suggestion I would make for the future, if all the users are using 2016 is to use Power Query which comes standard with that version of excel. In the Power Query loading data into Power Pivot scenario, all Power Pivot cares about is the column names. This means that the query can be changed between data source types without causing issues, as long as the same column names are changed.
As an example, I have one file that based on a parameter flag rips data out of a series of excel files on a shared network drive or Share Point. Both of which would be different data sources. The first opening a folder as the data source, then excel files listed within the folder. The other opening a share point list as its data source, then navigating though excel files.