Katalon 10.4.3 freezes when running multiple Test Suites (Java 23)

Web Testing
1

Hi everyone,

I am using Katalon Studio 10.4.3 with Java 23 on Windows.

When I freshly open Katalon and run a Test Suite, it executes successfully and generates the report without any issues. However, when I try to run another Test Suite afterward (without restarting Katalon), it gets stuck on: “Preparing to build your project”

After waiting for a long time, Katalon becomes Not Responding, and I am forced to end the task and restart Katalon to continue.

Has anyone else faced this issue with the latest version?
Are there any recommended workarounds or configuration changes?

Thanks in advance!

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2

Problem Analysis

You’re experiencing a specific issue with Katalon Studio 10.4.3 where:

  • :white_check_mark: First test suite run: Executes successfully
  • :cross_mark: Second test suite run (without restart): Gets stuck on “Preparing to build your project” and becomes unresponsive

Key Finding: Java 23 Compatibility Issue

Your use of Java 23 is likely the primary cause. According to Katalon documentation and community reports, Katalon Studio officially supports Java 17 only. Java 23 is not supported and can cause compatibility issues, including hanging and unresponsiveness during test execution.

Secondary Issue: Known Hanging Bug in 10.4.3

The release notes for Katalon Studio 10.4.3 document several fixes related to hanging issues:

  • Fixed an issue where moving multiple test cases up/down in test suite causes KS to hang
  • Fixed an issue where opening or switching custom keywords causes prolonged loading
  • Fixed an issue where renaming object or test case folders causes KS to hang
  • Fixed an issue where dragging and dropping objects causes KS to become unresponsive

While these specific fixes don’t directly address consecutive test suite execution, they indicate that version 10.4.3 had multiple hanging-related issues that were addressed.

Solution / Recommended Steps

Step 1: Switch to Java 17 (CRITICAL)

This is the most important fix:

  1. Verify your current Java version:

    • Open Command Prompt and run: java -version
    • You should see Java 17.x.x

  2. Download Java 17:

  3. Configure Katalon Studio to use Java 17:

    • In Katalon Studio, go to: Window > Preferences > Katalon > Java
    • Set the JRE to Java 17
    • Click Apply and Close

  4. Restart Katalon Studio completely

Step 2: Clean Up Your Project

After switching to Java 17, perform a project cleanup:

  1. Go to File > Clean up…
  2. Select your project
  3. Click OK
  4. Restart Katalon Studio

Step 3: Test Consecutive Runs

  1. Run your first test suite
  2. Without restarting Katalon, run your second test suite
  3. Monitor if the “Preparing to build your project” issue persists

Step 4: If Issues Continue - Additional Troubleshooting

If the problem persists after switching to Java 17:

  1. Increase Heap Memory:

    • Go to File > Settings > Katalon > Execution
    • Increase the heap size (try 2048 MB or higher)

  2. Clear Katalon Cache:

    • Close Katalon Studio
    • Navigate to: C:\Users\<username>\AppData\Local\Katalon\Katalon Studio
    • Delete the .metadata folder
    • Restart Katalon

  3. Disable Antivirus Temporarily:

    • Some antivirus software can interfere with Katalon’s build process
    • Temporarily disable it to test

  4. Remove Extra Profile Files:

    • Navigate to your project’s profiles folder
    • Delete any extra .glbl files (keep only default.glbl)
    • Restart Katalon

Key Considerations

Java Version Compatibility:

  • Katalon Studio 10.4.3 is built on Eclipse 4.33 and requires Java 17
  • Java 23 introduces breaking changes that are incompatible with Katalon’s underlying framework
  • Even though Java 23 may appear to work initially, it causes issues during consecutive executions due to memory management and class loading differences

Why It Works on First Run:

  • The first run initializes the JVM and loads all necessary classes
  • Subsequent runs attempt to reuse the same JVM instance, which can cause conflicts with Java 23’s stricter memory management

Hanging During “Preparing to build”:

  • This phase involves Gradle compilation and dependency resolution
  • Java version mismatches can cause the Gradle daemon to hang or become unresponsive

References

Next Steps: Please switch to Java 17 and report back if the issue persists. If you continue to experience problems after implementing these solutions, you may want to create a support ticket with Katalon.

3

hi @appsadmin

recommended workaround is to switch back to a supported Java version (Java 17 or 11) and try to restart Katalon
most people seeing this issue report it goes away immediately after downgrading Java.
also worth disabling auto-update and background build tasks if you’re running large projects

1 Like
4

Thank You for the information I will downgrade the Java version and will do all the necessary thing That you have given.

1 Like
5

Please do and let us know if it worked for you.