Sitecore Social Connected 2.1 is not compatible with Sitecore CMS 7.2.
The following error message can be displayed when using the Sitecore Social Connected 2.1 module on top of Sitecore CMS 7.2:
Could not find configuration node: contentSearch/configuration/defaultIndexConfiguration/analyzer
* Required changes to the Sitecore.Social.config file:
<analyzer ref="contentSearch/configuration/defaultIndexConfiguration/analyzer" />to:
<analyzer ref="contentSearch/indexConfigurations/defaultLuceneIndexConfiguration/analyzer" />
<initializeOnAdd>true</initializeOnAdd>