If you are unable to FTP into a server, it could be due to a few reasons and I will cover them below so that you will know what to expect and if it is possible to correct on your own.
The “Maximum Connections” is a server-wide value and when it comes to the server, the “Maximum Connections = 50” is considered to be a small value. Because of this small value, it shows as “we have too many connections” therefore, I always increase the Maximum Connections from 50 to 150.
Are you having firewall issues? Try and enable the FTP passive ports in the firewall as this often reduces firewall issues that you may experience.