Error #0159: your IP is not in the allowed addresses list
IP address of your device is not in MyChat "white" address list for allowed connections. Application type (Windows, Linux, macOS, Android и т.п.) does matter too.
Check the "white" list of IP addresses and application type that are allowed to connect to MyChat Server. Admin Panel, "Filters", "IP filters", "Allowed IP addresses".
If you connect from Admin Panel and the server does not let you in, try to connect from the same computer where MyChat Server works.
Connections from localhost (IP 127.0.0.1) are not filtered.