CloudFlare installation is failing with the error below:
Error: Installation of CloudFlare for Parallels Plesk at http://domain.tld/CloudFlare failed. Non-zero exit status returned by script.
Host API key is absent or invalid.
Enable Plesk debug logs and open http://domain.tld/CloudFlare to see, that CloudFlare installation is failed with the below error:
stdout: <p>Error Encountered:</p><p><ul><li>No or invalid host_key.</li></ul></p>
"Host API key" in CloudFlare application settings is not valid, and Plesk could not send request to CloudFlare site. Please contact CloudFlare support, in order to get a proper hosting API key. The following link can be referred for the details:
Please use this form to get Host API key from CloudFlare: