Use the Acquia Search module messages on a Search API server or on an index page to understand why the module is failing.
If the module is trying to connect to localhost or to the IP address 127.0.0.1, the Acquia Search module is not configured as expected or cannot detect the appropriate search index based on environment variables.
Check that the Drupal site can properly reach the Acquia Search API service, which provides the list of available Solr indexes for your application to your Drupal site. To check the site connection with the Acquia Search API Service, complete the following steps:
Navigate to the Search API Server you are trying to configure.
Click Edit.
If properly connected, the system displays a list of available search indexes in the SOLR INDEXES CURRENTLY AVAILABLE FOR YOUR APPLICATION box.
If you are running the Acquia Search module on a non-Acquia environment, you must use $settings['acquia_search']['override_search_core'] to point the module to a search index. For more information, see README.txt.