Sorry, the file you are trying to upload is not authorized (authorized extensions: jpg, jpeg, png, gif, zip).
Please allow files with no extension, .txt etc. to be uploaded.
Allowing files with no extension seems a little dangerous to me, but other extensions like .txt sound reasonable.
I just enabled more file extensions. The current allowed list is:
Figure: jpg, jpeg, png, gif, pdf, tif, tiff, ps,
Data file: txt, dat
Other: zip
Let me know if any common file extensions are still missing.