If you are using Sitecore 10.0 or an older version, you might face a problem when trying to unpublish an item from the web database or even delete an item before publishing its parent.
This occurs because of an inconsistency in Sitecore related to the “_indexname” Solr field. This field is stored on Solr using the “string” field type while it should be stored as “keyword”. Please note that this is fixed for 10.1 or later.
This causes an error when Sitecore identifies a delete or unpublish operation and tries to inform Solr that this item should be removed from the index. As you can note in the below images, Sitecore always stores the index name as lowercased, but for some reason it uses the original value with capital letters when performing the delete call on Solr.
SearchStax has created a workaround which is already part of the 1.4 release of the SearchStax Cloud Connector for Sitecore, so if you use this or a newer version you should not have this problem. If you are using an older version, the best solution is to upgrade the package to a newer version.
If that’s not possible, please contact SearchStax support team. They will create a new SearchStax index core which hasn’t any capital letters on its name. This guarantees that any delete operation from a Sitecore index works even if using Sitecore 10.0 or lower version.