The 'Unable to Access Jarfile' error means the Minecraft launcher cannot locate the game executable. This happens when the game files are missing (incomplete download, manual deletion), moved to a different path, or when file permissions prevent the launcher from reading them.
Usually client-sideLast verified: 2026-08-19
Re-download the game version
In the Minecraft Launcher, go to Installations, select your installation, click Edit, and set the Game Version to your desired version. Click Save and Play — the launcher will re-download the missing .jar file.
Check file permissions
Right-click the .minecraft folder > Properties > Security tab. Verify your Windows user account has Full Control. If not, click Edit and grant Full Control to your account.
How to fix step by step
- 1In the Minecraft Launcher, create a new installation or edit the existing one and re-select the game version — this re-downloads the .jar
- 2Navigate to %AppData%\.minecraft\versions\ and verify the game version folder exists with a .jar file inside
- 3Right-click the .minecraft folder > Properties > Security — grant your user account Full Control
- 4Temporarily disable antivirus (which may have quarantined the .jar) and try again
How UNABLE-TO-ACCESS-JARFILE differs from related codes
- Error FAILED-TO-DOWNLOAD: The Minecraft Launcher failed to download one or more game files needed to launch. The download was interrupted or a file was corrupted. (server or client)
- Error EXIT-CODE-1: The Java Virtual Machine running Minecraft crashed and exited with code 1, indicating a fatal error. This is typically a Java or mod compatibility issue. (user-side)
- Error CRASH-REPORT: Minecraft's Java Virtual Machine (JVM) encountered a fatal error that could not be caught by the game. A crash-report or hs_err_pid log file was created containing the stack trace and error details. (usually client-side)