The sitecore_testing_index and sitecore_suggested_test_index are not found after deploying a solution using the Azure Marketplace with the Solr search provider. The issue happens due to incorrect core names of the current indexes. Other indexes use a dynamically defined name $(id), but those two indexes have it set explicitly, and to a non-standard value. The following error message might appear in the log:
ERROR Unable to connect to [https://ss680690-37h4xtb0-northeurope-azure.searchstax.com/solr], Core: [Sitecore-sitecore_testing_index] Exception: SolrNet.Exceptions.SolrConnectionException Message:
<html> <head> <meta http-equiv="Content-Type" content="text/html;charset=utf-8"/> <title>Error 404 Not Found</title>
To resolve the issue, change the explicitly defined "core" names to dynamic ones as follows:
<param desc="core">Sitecore-sitecore_testing_index</param>and
<param desc="core">Sitecore-sitecore_suggested_test_index</param>to dynamically defined values:
<param desc="core">$(id)</param>