Most people searching for this specific string are troubleshooting. There are three primary reasons this keyword pops up: A. CORS Policy Restrictions
Thus, the most plausible interpretation is: fetch-url-file-3A-2F-2F-2F
If you are running into specific errors, such as a "null" response when fetching local resources, developers on GitHub often discuss workarounds for blob handling and URI schemes. Most people searching for this specific string are
fetch-url-file-3A-2F-2F-2F decodes to fetch:///// fetch-url-file-3A-2F-2F-2F
