FAQ Why does my update site need a license?
When installing a feature using the Update Manager, you may run into a cryptic message that this feature will invalidate the current configuration. When you click Details..., the reason is indicated: A license agreement is missing for the feature. A feature must have a license before it can be shared with others on an update site.
For each feature published through your update site, edit the feature.xml file and enter a license agreement. Then, in the site.xml editor, click Build All again to rebuild the features.