If you are having problems with Site to Object Mapping and Metadata Mapping, check your level of Java. If you are running with Java 7, you might see this message:
org.springframework.social.salesforce.api.SalesforceRequestException: TLS 1.0 has been disabled in this organization.
Please use TLS 1.1 or higher when connecting to Salesforce using https.
Salesforce requires access to the API using TLS 1.1 or 1.2. You can enable TLS 1.1 and 1.2 in Java 7 using JVM parameters, but they are enabled by default with Java 8. See Diagnosing TLS, SSL, and HTTPS and JDK 8 will use TLS 1.2 as default for more information.