Only the latest versions of AIMP are supported: AIMP v4.11, build 1841 from 09.10.2016 and newer.
It is desirable to protect connection by setting a password in settings.
Plugin settings can be found in AIMP's settings, under Remote Control section.
App shows "Update plugin", but it is already updated
Ensure that your antivirus or firewall (including Windows Firewall) is not blocking connection on port 3333 (default). Also, port 3332 is used to discover computers. In plugin settings you can see addresses that can be used to access plugin.