Unable to Access JarFile: 3 Ways to Run JAR Files

Java browser plug-ins might have gone out of fashion, but many programs run off Java. For example, you can open Java programs with JarFiles, among other software for opening JAR files.

However, some Java software users can’t always open JAR programs with the Unable to access JarFile error message popping up. This guide will show you some practical ways to get past this error message.

Why does it say unable to access jar?

The inability to access JarFile on Minecraft or Forge can be caused by mistakes on your path or issues with the software. Below are some of the prevalent causes:

• Outdated Java version: If your Java version is obsolete, you cannot access JarFile using the docker container. You need to update Java to the latest version.
• Wrong default program: Sometimes, this issue might be because you have not set the default program to open the JarFiles. Choosing Java as the default app for opening JAR files should fix this.
• Issues with the JAR file path: If the path to your jar file is incorrect, you can get this error. The solution here is to ensure the path is correct.

How can I fix the unable to access JarFile error?

Before proceeding to the fixes in this guide, try the preliminary troubleshooting steps below:

• Add .jar extension to the JAR file name
• Beware of spaces in the JAR file path
• Add quotes to the JAR file path if it contains space
• Move the JAR file to another folder
• Use a file opener software

If the fixes above fail to solve the issue, you can now move to the fixes below:

1. Update your Java version

1. Press the Windows key + R, type appwiz.cpl, and click OK.
   
2. Right-click the Java app and select the Uninstall option.
   
3. Now, go to the official website to download the latest version of the Java app.

A broken or outdated app can cause the unable to access the JarFile issue. Downloading the latest version of the app should fix the problem.

2. Select Java as the default program for JarFiles

1. Open File Explorer and the folder that includes your JAR file.
2. Right-click the file and select Open with, and then Choose another app.
   
3. Select Java if it’s listed among the default programs.
4. If Java isn’t listed among the programs, select the Look for another app on this PC option.
   
5. Then browse to the Java bin folder, select  Java and press the Open button.

JAR file error messages usually pop up when Java isn’t configured as the default software for a JAR file. This can be the cause of the unable to access JarFile.

Setting Java as the default program should fix the issue here.

3. Open the Jarfix Software

1. Click jarfix.exe on this webpage to save the software to a folder.
   
2. Now, open the folder and double-click the jarfix.exe option.
   
3. The tool will start and fix issues with your jar file extension.
   

In some cases, the unable to access JarFile issue on IntelliJ can be because of problems with the file type associations. This Jarfix.exe software will help you fix this issue and restore normalcy on your PC.

Those are a few resolutions that might fix the unable to access JarFile error and kick-start your Java software. After that, you only need to follow the instructions carefully, and the issue should be resolved.

For further details on installing a JAR file in Windows 10, check our guide to make the process easy.

If you have any other questions, please leave them in the comments section below.