Sometimes, you may get the above error while trying to activate the installed custom feature in your SharePoint server.
Error message says you are trying to install a feature with an invalid scope; there are certain elements that can’t be added to some scopes (Farm, Site, Web, and WebApplication). To get the installed feature, browse to
c:\program files\common files\ Microsoft Shared\Web server extensions\12\templates\Features.
To get rid of this error message, try to change the ‘Scope’ attribute to either ‘Farm’ or ‘Site’ or ‘Web’ or ‘WebApplication’.
Also, try to do that through STSADM.EXE.
· stsadm -o installfeature -filename MyCustomFeature\feature.xml
· stsadm -o activatefeature -filename MyCustomFeature\feature.xml –url http://Server/Site/
Eg: I am giving a sample feature.xml file which configured for Site level.