The source-control system you are using must be enabled.

To enable a provider:
  1. Choose Tools > Options or press Alt+,.
  2. Select the Source Control category in the options dialog.
  3. Set the Source Control Provider to the appropriate provider.
  4. Set the provider-specific options.
  5. Set Enable Source Code Control Integration to Yes.

Note: The source-control provider information is stored in the CrossWorks global environment, so you can only use one provider for all your CrossWorks projects.