Neo4J start, but crashes: "Neo.DatabaseError.Transaction.TransactionStartFailed"

I have installed server neo4j on linux. It was working before, but now it crashes every time. I initiate Neo4j via ./bin/neo4j start. It loads up. I access via web browser at 7474, but get this error ""Neo.DatabaseError.Transaction.TransactionStartFailed". Abridged log and debug output below. How to fix this?

This is the error from the neo4j.log

INFO Starting...
WARN The client is unauthorized due to authentication failure
ERROR Client triggered an unexpected error (Neo.DatabaseError.Transaction.TransactionStartFailed] : The database has encountered a critical error and needs to be restarted. Please see database logs
ERROR Failed to start Neo4j: Starting Neo4j failed: Component 'org.neo4j.server.database.LifecycleManagingDatabase***' was successfully initialized, but failed to start. Please see the attached cause exception..
...

This is the error from debug.log:

Suppressed : org.neo4j.kernel.impl.store.UnderlyingStorageException: Failed to flush
Cause by: java.io.FileNotFoundException: $NEO4j_HOME/data/database/graph.consume_complaint.db/neostore.counts.db.a (No such files or directory) (edited)