Why does my image import fail due to 'too many redirects' error?

[sap]

I've used the same path to my jpg files before and when I click on the links Shopify says aren't working, the images load. But Shopify won't import them. 

"147 products couldn't be changed due to invalid information
To import products that couldn't be updated, fix any errors in the CSV file and try importing it again.
Failed: Line 2: Validation failed: Image https://archive.track16.com/artimages/collins_11675.jpg failed to download. - too many redirects. Check the image URL and try again."

I've checked the URL and tried again many times. 

[thinkitfirst1]

We're having the same issue. Unclear why this started happening, as it was not a concern at least a year ago when our code went live.

Attempting to upload a new image to a product using the Admin API, like so, fails:

POST /products/########/images.json

{"image":{"src":"http://ourdomainname.com/wp-content/uploads/2021/03/our_image.jpg","position":1}}

(leaving out identifiable information) 

I've verified that the image URL is valid and can be accessed in a browser. But the image upload fails with 422

Unprocessable Entity error. Why?