A WordPress security plugin or server firewall could be preventing the export to proceed. Cloudflare's Web Application Firewall (WAF) for instance automatically rejects unfamiliar HTTP requests. Clearly, this is a false positive as our plugin uses legitimate HTTP payloads when exporting your data, as seen below: To resolve this issue, ask your developer or host to temporarily disable firewalls or whitelist all incoming HTTP requests from your site's /wp-admin/.