Some extensions fail in AE 18.4 and later version

[seer5E81]

like atomX or AEviewerBP or Beats edit,how to solve it?

[Rick Gerard]

Contact the extension authors. All kinds of software must be updated to work with OS and App version changes. Some never get fixed. 

The other option is to roll back an AE version or have the latest installed. I keep two or three versions on my system all the time to try and prevent as many of these kinds of problems as I can.