Problem

Control Center is unable to connect to neoControl because neoControl does not run properly.


Cause

When opening the page in browser localhost:49098, neoControl is not displayed. The problem might occur because the installed Java version in the system is not compatible with neoControl.


Verification

  1. Generate the neoControl logs to diagnose the issue. 

  2. Look for the following events in the logs:

    NEXT_ROOT is not defined -- WORootDirectory and WOLocalRootDirectory set to empty string! java.lang.UnsupportedClassVersionError: neocontrol/app/Application : Unsupported major.minor version 52.0    at java.lang.ClassLoader.defineClass1(Native Method)    at java.lang.ClassLoader.defineClassCond(Unknown Source)    at java.lang.ClassLoader.defineClass(Unknown Source)    at java.security.SecureClassLoader.defineClass(Unknown Source)    at java.net.URLClassLoader.defineClass(Unknown Source)    at java.net.URLClassLoader.access$000(Unknown Source)    at java.net.URLClassLoader$1.run(Unknown Source)    at java.security.AccessController.doPrivileged(Native Method)    at java.net.URLClassLoader.findClass(Unknown Source)    at java.lang.ClassLoader.loadClass(Unknown Source)    at java.lang.ClassLoader.loadClass(Unknown Source)    at com.webobjects._bootstrap.WOBootstrap.main(WOBootstrap.java:84)

  3. If these events are present, the issue is caused by an incompatible Java version.


Solution

Follow these steps to resolve the issue:


1. Check which version of Java you have: Go to Applications & Features and look for Java. If your version is older or newer than 8, you need to update your Java version.


2. Update the Java Version:

  • Option A: Uninstall Java and Reinstall neoStampa. This will install the correct version of Java automatically.

  • Option B: Update Java Manually. Download the latest compatible version of Java from the official website:
    Java Manual Download


3. Restart the Computer: A system restart is necessary to ensure all changes are applied correctly.

4. Reconnect to the Data Source: 

  • Open the Control Center Preferences

  • Connect to the data source by following the normal process.


5. Verify Printing History:

  • Go to the Printing History tab.
  • Refresh the view to ensure printers are loaded correctly.