A JAR is a package file format which is used by many Java class files with the associated metadata and resources to get packed in a single package for distribution. Sometimes, the "unable to access jarfile" error will occur when you open it. You can read this post from MiniTool to fix this error.

What Causes the "Unable to Access Jarfile" Error

There are several different reasons for the "Java unable to Access Jarfile" issue. Most of them are related to the handling of JAR files on your computer.

1. The latest Java version has not been installed on your computer.

2. The file path set for the Java executable is incorrect and points to the wrong location.

3. The default program for opening JAR files is not set.

4. Malware is on your computer.

Tip: You should ensure that you have an active internet connection and administrator account privileges before you move on to the methods.

How to Fix the "Unable to Access Jarfile" Error

  1. Install the Latest Java Version
  2. Set the Default File Association
  3. Check for Malware
  4. Check for Documentation (for Developers)

How to Fix the "Unable to Access Jarfile" Error

Method 1: Install the Latest Java Version

You need to install the proper architecture i.e. Java on your computer for programs to run JAR files. Furthermore, it should be the latest version released. Here is the tutorial.

Step 1: Press the Windows + R keys at the same time to open the Run dialogue box, then type appwiz.cpl and click OK to open the Programs and Features window.

Step 2: Then navigate to the entry of Java and right-click it, then click Uninstall.

Step 3: Then go to the official Java website and download the latest version. Run it to install the latest version of Java after you download the executable.

Restart your computer and check if the "Unable to Access Jarfile" error message has been resolved.

Method 2: Set the Default File Association

If you are still unable to access jarfile Minecraft, you can try changing the file association. Here are the steps.

Step 1: Navigate to the JAR file's directory. Right-click it and select Open with and select the Java program.

Tip: If you do not get the option right away to open as Java, you can click Choose another app and select Java.

Step 2: Then press the Windows + I keys to launch the Settings application. Now navigate to Apps and select Default apps from the left navigation bar.

select Default apps from the left navigation bar

Step 3: Now click Choose default apps by file type present at the near bottom. Now locate the entry .jar file and make sure it is selected to be opened by Java.

Step 4: Then you should save changes and exit.

Restart your computer and check if the "unable to access jarfile" error message is resolved.

Method 3: Check for Malware

You should check if there is any virus or malware on your computer if you are still receiving the error when you start your operating system or any program.

You should run a thorough check on your computer and then follow method 1 to ensure all the entries and file associations are deleted and then remade when you reinstall Java. Here is how to remove malware after you check, read this post - How To Remove Malware From A Windows Laptop.

Method 4: Check for Documentation (for Developers)

If you are a developer coding with Java or other languages, you also encounter this error message when you try to start a JAR file. This can be really troublesome and will probably halt your task at hand.

It is recommended that you read the documentation for the function or utility that opens or runs the JAR file to diagnose and solve the error. You may have mistaken the file path, or you may have passed the wrong parameter to the function.

Final Words

You can know the reasons for the "Java unable to Access Jarfile" issue and 4 useful methods that can fix the error from this post. I really hope that this post can help you.

About The Author

Daisy

Position: Columnist

She was graduated from the major in English. She has been the MiniTool editor since she was graduated from university. She specializes in writing articles about backing up data & systems, cloning disks, and syncing files, etc. She is also good at writing articles about computer knowledge and computer issues. In daily life, she likes running and going to the amusement park with friends to play some exciting items.