Most likely, the link does not meet the following requirements:
The link provided must lead to a specific video or photo. It will be rejected if the link leads to search engine results, a redirect, or the home page of a third-party source.
The photo or video must contain the logo of our site and/​or the DMCA security mark. In their absence, it is almost impossible to remove the content, so the link may be rejected. The link may also be rejected if the video or photo contains only the DMCA security mark, but the lawyer has determined that the content belongs to another copyright holder (it is indicated that this is a professional or amateur shooting, the content is recorded on another source, there are elements of a third-party site, etc.)