1. First change the managed schema to schema.xml in /var/solr/data/core??/conf/managed-schema. And copy or edit your desired file to it. You can follow the below link. What it said to remove ManagedIndexSchemaFactory from solrconfig.xml . You might not find the ManagedIndexSchemaFactory to remove. but don’t worry. if it is not there then its ok. And add
2. Change the field type if necessary in schema.xml. Check in the log of solr admin. You should also check in the /var/log/apaceh2/error.log
In my case I had to add lots of field like
3. Restart the solr and try to connect the core from your application. For php I got a 404 because the connection denied. I see the log and found this Indexschema is not mutable. Search the google for “org.apache.solr.common.SolrException: This IndexSchema is not mutable” and found the solutions there.
You need to remove the AddSchemaFieldsUpdateProcessorFactory section from the updateRequestProcessorChain config in your solrconfig.xml and thats it for me. while restarting the solr service my app again connected to the solr 6.4 and start indexing my docs.
Always try to find out what is the problem in you solr admin log, apache log, and in my case my local app log also helped. I was using zend for solarium in php.