Could not resolve type name: Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider

Question

I am configuring solar and lucen both together for different index (master and web ) in sitecore . I am using 4.1 solar and sitecore 8.1.

I've enable both Sitecore.ContentSearch.Solr.DefaultIndexConfiguration and Sitecore.ContentSearch.lucen.DefaultIndexConfiguration config and respective index config. while rebulding the index I am getting below error

Could not resolve type name: Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider (method: Sitecore.Configuration.Factory.CreateFromTypeName(XmlNode configNode, String[] parameters, Boolean assert)).

What are the possible causes for above error?

Answer 1

It means that Sitecore.ContentSearch.SolrProvider.dll is not in your bin directory.

Download Solr support package for your Sitecore version from dev.sitecore.net and copy dlls from it.