# Unsupported or unrecognized SSL message

> The FTPS Transport is set to explicit FTPS over port 21. Cascade CMS supports implicit FTPS only, typically over port 990.

URL: https://www.hannonhill.com/cascadecms/latest/articles/content-authoring/publishing/unsupported-or-unrecognized-ssl-message.html
category: Content Authoring
article-type: troubleshooting
content-kind: faq
release-availability: all
tags: publishing, errors, security
updated: 2026-10-06

The following error may appear when publishing to a web server via FTPS:

```bash
Could not connect to FTPS server (host:21) : Unsupported or unrecognized SSL message
```

This occurs when the FTPS Transport is configured to connect using *explicit* FTPS over port `21`. Cascade CMS supports *implicit* FTPS only. To correct it:

1. Configure the target FTPS server to allow implicit connections, typically over port `990`.
1. Adjust the corresponding FTPS [Transport](https://www.hannonhill.com/cascadecms/latest/articles/content-authoring/publishing/transports.html) in Cascade CMS to connect using port `990`.