The error was very generic and not helpful
error : Failed to read in the data for the path/file [..\<path>\<filename>]. The most common cause for this is because the path is incorrect or the file name is incorrect … so please check your path and file names. Until you fix this up, I can’t continue … sowwy.
The file was present and seemed to be syntactically correct and all.
Renaming it fixed the issue.