I'm set Breckets, it automatically creates the extension folder in the <Users>\AppData\Roaming\Adobe\CEP\extensions\, but the extension menu in Photoshop doesn't appear. 3-4 months ago made the extension "Hellow world" and it was installed, but the new expansion does. Read the manual, checked the registry key, copied in the extension folder c:\Program Files\Common Files\Adobe\CEP and c:\Program Files (x86)\Common Files\Adobe\CEP did not help.
Tell me please where you want to save the extension depending on the version.
check the manifest.xml file.
Very likely the HostList doesn't have the correct version, such as:
<HostList> <Host Name="PHXS" Version="16.0" /> <Host Name="PHSP" Version="16.0" /> </HostList>
Give that a try, reboot PS and let us know.
Yes, Breckets by default puts 15.0 - 15.9