What does the error "Existing open connection detected" mean?

General Newbie Questions
1

Hello. During a query to my Neo4j database, I encountered the following error:
java.util.concurrent.CompletionException: java.lang.IllegalStateException: Existing open connection detected

Does someone know what caused this error, and how to solve it ? Thanks a lot!

2

On what type of instance are you running this query (Neo4j Aura, cloud provider, Neo4j Desktop, somewhere else)? Sounds like there may be an existing query hanging up the connection.