"Couldn't find Canvas CSV import headers" - SIS error

[kawaters]

Hello,

We are using CURL and when I try to import terms.csv or any file, I get " Couldn't find Canvas CSV import headers"

I know the file is fine because when I try to manually upload it, it goes through. 

Any thoughts why Im getting this error?

Thank you!

[gyang2]

I am using API to do SIS_import and I got the same error "Couldn't find Canvas CSV import headers" sometime, not always (once a week).

What the problem it could be?