I got many failed websites with status "download failed (no content)"

seoetraffic

Hi
I have about 1m7 website URLs, i just tested with 1k URLs and 720 failed , 106 sent
all failed with this status 
"download failed (no content)"
here are some sites with that failed message:
http://www.vardhmanhealth.com/contact-us/
https://fishlinehelps.org/contact/
https://www.12piecesatatime.com/contact
http://www.cbh.mk/contact/contact.html
https://swankyagency.com/contact-us/
https://www.pasoroblesbiblechurch.com/contactus
http://www.mainstreetdental.co.uk/contact/
https://valeriestewartportraits.com/contact/

I don't know why they are failed 

Sven

probably a proxy issue