I am trying to configure Solr for Sitecore 8.2. Solr is running and I have cores set up for each index and secondary cores set up for rebuilding. I'm not using the Solr support package.

I am getting the following error when trying to browse the site: 

>Could not create instance of type: `Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex`. No matching constructor was found.

I'm guessing, it's a configuration problem. However, I can't get to `showconfig.aspx` to see what the issue might be. 

Below is the patch config for the indexes:

<!-- language: lang-xml -->

    <indexes>
      <index id="sitecore_core_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_core</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_core_2</param>
      </index>
      <index id="sitecore_master_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_master</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_master_2</param>
      </index>
      <index id="sitecore_web_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_web</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_web_2</param>
      </index>
      <index id="sitecore_marketing_asset_index_master" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_marketing_asset_master</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_marketing_asset_master_2</param>
      </index>
      <index id="sitecore_marketing_asset_index_web" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_marketing_asset_web</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_marketing_asset_web_2</param>
      </index>
      <index id="sitecore_marketingdefinitions_master" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_sitecore_marketingdefinitions_master</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_sitecore_marketingdefinitions_master_2</param>
      </index>
      <index id="sitecore_marketingdefinitions_web" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_sitecore_marketingdefinitions_web</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_sitecore_marketingdefinitions_web_2</param>
      </index>
      <index id="sitecore_testing_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_testing</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_testing_2</param>
      </index>
      <index id="sitecore_suggested_test_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_suggested_test</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_suggested_test_2</param>
      </index>
      <index id="sitecore_fxm_master_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_fxm_master</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_fxm_master_2</param>
      </index>
      <index id="sitecore_fxm_web_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_fxm_web</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_fxm_web_2</param>
      </index>
      <index id="sitecore_list_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_list</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_list_2</param>
      </index>
      <index id="social_messages_master" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_social_messages_master</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_social_messages_master_2</param>
      </index>
      <index id="social_messages_web" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <patch:attribute name="type" value="Sitecore.ContentSearch.SolrProvider.SwitchOnRebuildSolrSearchIndex, Sitecore.ContentSearch.SolrProvider"/>
        <param desc="core">SitecoreSandbox_social_messages_web</param>
        <param patch:after="*[@desc='core']" desc="rebuildcore">SitecoreSandbox_social_messages_web_2</param>
      </index>
    </indexes>