@Rpsada Welcome to the community.
The error SSL_ERROR_NO_CYPHER_OVERLAP typically occurs when your browser cannot establish a secure connection with the Square Online website due to incompatible SSL/TLS settings or outdated browser configurations.
Are your customers getting also or just you? If it is just you then a there is a couple of things you could try.
1. Clear your browser cache.
2 Make sure your browser is updated to the latest version.
3. If you are running a antivirus or firewall temporarily disable SSL in your antivirus scans.
If none of this works, then I would contact support and have them look at your SSL configuration, I have read another thread that is having a problem similar to yours, so it may be something Square technical support will have to fix on their end.
