This error means that the server and client (browser) are unable to establish a secure connection between them. To establish a secure connection between the server and client they need to have a cipher in common to understand each-others messages. If the ciphers don’t match the server and client can’t communicate and it results in this error.
The first step in debugging this issue is to check whether the issue occurs in multiple browsers. If the error occurs only in one browser, try to update the browser and clear the browsers cache. If that doesn’t solve the issue it likely has to do with a lack of defined ciphers in the server configuration. Update the available ciphers in the server configuration to solve this error. This is something your hosting provider can help with, they will have access to the server configuration and can make the necessary changes for you.