SQL Developer runs by default in "Remote Debugger" mode. It means that SQL Developer listens on a port for events coming from the Database. This allows the developer to debug a PL/SQL either launching it from the tool or even from a different session, e.g. from a Web Application while watching what is going on in the IDE window. This is a very smart option but requires SQL Developer to listen and Database to send events to the tool.
When running the Database in Cloud, the debug session will probably fail because your workstation is not accessible from the internet and the port SQL Developer is listening on is not open on the corporate firewall.
You then have two solutions:
- ask your network admin to open the firewall and let your IP address to be published on the Internet, or
- disable "Remote Debugging".
To disable "Remote Debugging" exit SQL Developer and insert the line:
into ide.properties file, which is usually located in: