Summary: When using dynamic navigation to refine the query the browser suddenly displays the error "Unable to fetch <QUERY STRING>. The index may not be ready. Try again in a minute." on the page.
Cause: Repeated use of dynamic navigation extends the search query by further inmeta query terms. Once the search url grows past the limits documented in the search protocol reference, an error will be returned.
Troubleshooting Steps: In order to be sure that the length of the query term is the root cause, use the back button of the browser and experiment with the query term length.