java.nio.file.AccessDeniedException (File or Folder Access Denied)

What the log looks like

java\.nio\.file\.AccessDeniedException:\s+\S+

How to fix it

1. Check the exact path printed right after `java.nio.file.AccessDeniedException:` in your crash log to identify which file or folder Windows is blocking.
2. If the path points to a hidden system folder like `Config.Msi` or `System Volume Information`, change your game directory in your launcher settings to a dedicated subfolder (for example, `F:\Minecraft\`) rather than the root of a drive (`F:\`).
3. Verify your launcher's game and installation paths for typos (such as a missing slash like `Roaming.minecraft`) or broken symbolic links (`mklink`) whose target drive or folder no longer exists.
4. Open Task Manager (`Ctrl + Shift + Esc`) and end any leftover `javaw.exe`, `java.exe`, or launcher processes that may be holding a lock on the `.jar` file or directory.
5. Right-click your `.minecraft` or launcher data folder, open Properties > Security to grant your Windows user account Full Control, and add the folder as an exclusion in your antivirus or Windows Security Controlled Folder Access.

Check your own log