If you receive a warning when using merge fields that the image or video is blocked or can not be retrieved, it is normally caused by one of the following reasons:
The file has moved or is missing, i.e. 404 Not Found error
The file uses a security token or requires credentials, i.e. 403 Not Authorised error
The file can not be retrieved from your server due to CORS issues
If you receive this error, it means the video might still render via the API, but not display in the preview.
To resolve the issue, check that the test URL is correct, the file exists and is not blocked by CORS or any security protocols.
Get detailed instructions on using particular sources:
A note about CORS issues
By default, most web servers, hosting providers and storage locations do not allow other websites to download content from them. The is called Cross Origin Request Sharing (CORS). To allow Shotstack to retrieve media assets from your URL's you can modify the CORS policy to allow requests from our domain name shotstack.io.