: Regarding https://issues.apache.org/jira/browse/SOLR-758 (Enhance : DisMaxQParserPlugin to support full-Solr syntax and to support alternate : escaping strategies.)
FWIW: i'm not really sure what/how that issue relates to the problem you are seeing (or how you *think* it relates to hte problem you are seeing) ... so i'm just going to focus on the specifics of your error... : After applying the attached patches to 3.6.1 I'm experiencing this problem: The mailing list typically rejects patches - none came with your message. : - SEVERE: org.apache.solr.common.SolrException: Error Instantiating : QParserPlugin, org.apache.solr.search.AdvancedQParserPlugin is not a : org.apache.solr.search.QParserPlugin Besides the obvious problem of not extending the expect class, the other posibility is that when compiling you "AdvancedQParserPlugin" you may be compailing against the wrong version of solr -- ie: you could get this error if the AdvancedQParserPlugin.class file you have was generated when your AdvancedQParserPlugin.java file was compiled against a different QParserPlugin.class then the one in use at runtime. -Hoss
