Niagara Web Browser Java Download Issues

This article addresses common issues when browsers prompt for Java installation when connecting to Niagara/JACE systems, despite Java already being installed.

Understanding Niagara Web Access

Niagara offers multiple web access methods:

Method	Technology	Java Required?
HTML5 Web UI	Modern HTML/JS	No
Workbench Web Launch	Java Web Start	Yes (Java 8+)
Legacy Applet (AX)	Browser Plugin	Yes (deprecated)

Modern Niagara 4: Primarily uses HTML5, Java only needed for Workbench launch.

Niagara AX: May still use Java applets (being phased out).

Common Causes and Solutions

Cause 1: Using Wrong Access Method

Symptom: Browser prompts for Java when trying to view graphics

Solution: Use the HTML5 interface instead:

Instead of: https://192.168.1.100/Java
Use:        https://192.168.1.100/

Navigate to the station's web interface root, not the Java-specific path.

Cause 2: Browser No Longer Supports Java Plugins

Background: Major browsers removed Java plugin support:

• Chrome: Removed 2015 (v45+)
• Firefox: Removed 2017 (v52+)
• Edge: Never supported NPAPI
• Safari: Disabled by default

Solution:

• Use HTML5 web interface for viewing
• Use Java Web Start (.jnlp) for Workbench access
• Download standalone Workbench client

Cause 3: Java Web Start Configuration

For launching Workbench via browser:

Steps:

1. Install Java 8 or 11 (not newer - compatibility issues)
2. Download the .jnlp file from station
3. Associate .jnlp files with Java Web Start
4. Allow security exceptions for station URL

Finding JNLP file:

https://[JACE_IP]/ord?station:|slot:/|view:niagara:WebStartView

Cause 4: Wrong Java Version

Niagara 4 Requirements:

Niagara Version	Java Requirement
N4.0 - N4.7	Java 8
N4.8 - N4.10	Java 8 or 11
N4.11+	Java 11 recommended

Check installed version:

java -version

Solution: Install correct Java version, may need to uninstall newer versions that take precedence.

Cause 5: Java Security Settings

Symptom: "Application Blocked by Java Security"

Solution:

1. Open Java Control Panel (Windows: Control Panel > Java)
2. Go to Security tab
3. Add station URL to Exception Site List:
   • https://192.168.1.100
   • Include both HTTP and HTTPS versions
4. Set Security Level to High (not Very High)

Cause 6: Browser Security Blocking

For Chrome/Edge:

• Java plugins no longer work, use .jnlp method

For Internet Explorer (legacy):

1. Add station to Trusted Sites
2. Enable Java plugin in Internet Options
3. Clear browser cache
4. Disable Enhanced Protected Mode

Note: IE is deprecated; migrate to HTML5 or Workbench client.

Recommended Modern Approach

For Operators (Viewing Graphics)

Use HTML5 web interface - no Java required:

1. Open modern browser (Chrome, Firefox, Edge)
2. Navigate to https://[STATION_IP]/
3. Log in with credentials
4. Access HTML5 graphics

For Engineers (Workbench Access)

Use standalone Workbench:

1. Install Niagara Workbench on your PC
2. Open Workbench application directly
3. Connect to station via File > Open > Open Station
4. No browser involved

For Remote Workbench (when needed)

Use Java Web Start:

1. Navigate to station in browser
2. Download .jnlp file (not run in browser)
3. Open .jnlp file with Java Web Start
4. Workbench launches as separate application

Troubleshooting Steps

Step 1: Verify Java Installation

java -version

Should show Java 8 or 11.

Step 2: Check JNLP Association

• Right-click a .jnlp file
• Open With > Java Web Start
• Check "Always use this app"

Step 3: Clear Java Cache

1. Open Java Control Panel
2. Settings > Delete Files
3. Clear all temporary files

Step 4: Test Direct Connection

Try connecting with standalone Workbench to verify it's not a Java/station issue.

Migration Path

If still using Java-dependent interfaces:

1. Upgrade to Niagara 4.8+ - Better HTML5 support
2. Enable HTML5 graphics - Convert Hx views
3. Install standalone Workbench - For engineering access
4. Retire Java plugins - No longer maintainable

Browser Compatibility Matrix

Browser	HTML5	Java Plugin	JNLP Download
Chrome	Yes	No	Yes
Firefox	Yes	No	Yes
Edge	Yes	No	Yes
Safari	Yes	No	Yes*
IE 11	Yes	Limited	Yes

*Safari may require additional security permissions for JNLP.