When you attempt to delete a build environment that is in use (is attached to a Build Definition), Continuum refuses to delete it, but just displays "profile.remove.error" in red above the list.
Looks like it's either the wrong message key, or the key/value is missing from the resource bundle.
Please. Test in trunk. I am working in r757431 and I get message 'The Build Environment can't be removed, it is probably used by a build definition.' .
Sorry but I can't detect the revision when this message missed.