My Oracle Support Banner

SQL Developer Shows "Connection Closed" Error When Running a Query (Doc ID 1297692.1)

Last updated on AUGUST 04, 2018

Applies to:

Oracle SQL Developer - Version 2.1.1 and later
Microsoft Windows x64 (64-bit) - OS Version: 7
***Checked for relevance on 08-Sep-2012***
***Checked for relevance on 16-May-2014***


The creation of a new connection goes through fine and the "Test" connection functionality and returns success status. While trying to view any tables, functions, procedures, etc., a "connection closed" message is displayed. Also, running any query returns the same "connection closed" message.

The following error message is seen in the command window:

Exception initializing 'oracle.dbtools.raptor.plsql.PLSQLAddin' in extension 'Oracle SQL Developer': java.lang.NoClassDefFoundError: com/sun/jdi/Bootstrap at oracle.jdevimpl.debugger.jdi.DebugJDIConnector.getVersion(


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.