pdf file won't upload thru CoCalc UI

[DrXyzzy]

This pdf file won't upload through the CoCalc UI.

1. Copy the file at the link to your local computer.
2. In a CoCalc project, click (+)New.
3. Try any of the following:
   1. paste the link above into the "Name your file, ..." url at the top and press Enter
   2. drag and drop the copy of the file from your local computer into the upload dropzone
   3. click "Drop files..." and select the local file on your computer for upload
4. Note that the file is not copied. The second and third approaches show a 503 gateway error.

Notes:

• Upload is possible with scp.
• Renaming the local file to foo.pdf did not help with UI upload attempts in second and third approaches.

[williamstein]

Link is stale. Obviously pdf's upload fine these days.