We’ve been using CloudFlare SSL certs for our sites, and been trying to use them for FTP as well. However, we’re running into issues with the FileZilla client not accepting these certificates consistently.
Initially, when setting up the connection in FileZilla, the client prompts to trust the certificate. After clicking “OK,” the connection is successful, and I can browse the folder structure without any issues. But if I close FileZilla and attempt to reconnect later, I receive the following error: “Received certificate chain could not be verified.”
I’ve reviewed the certificate chain and don’t see any missing links or errors.
Interestingly, when I test the same connection in CoreFTP, it works without any problems. This makes me wonder if there’s something specific about how FileZilla handles certificate validation that’s causing the issue. Not sure where I would need to make the change to get it working.
