Resetting MapTool JVM Settings

Resetting MapTool JVM Settings

If you changed the JVM memory settings under Edit->Preferences, there is a possibility of adding an invalid value that will keep MapTool from starting.

The first method is to pass the -reset option to your MapTool executable. The location of the MapTool executable will vary based on operating system.

  • Windows: C:\Users\[username]\AppData\Local\MapTool\MapTool.exe -reset
  • Linux: /opt/MapTool/MapTool -reset
  • Mac: Varies but may be open /Applications/MapTool –args -reset

You can also manually edit the memory config file for MapTool to set the appropriate Java Virtual Machine (JVM) values. Deleting the jvmuserargs.cfg file has the same effect as the reset flag.

  • Mac: ~/Library/Application Support/net.rptools.maptool.client/packager/jvmuserargs.cfg
  • Windows: C:\Users\[username]\AppData\Roaming\net.rptools.maptool.client\packager\jvmuserargs.cfg
  • Linux: ~/.local/net.rptools.maptool.client/packager/jvmuserargs.cfg

The contents of the file will look something like

[JVMUserOverrideOptions]
-Xmx=4G
-Xms=4G

You then modify the -Xmx= to be something your computer will digest. We generally recommend setting -Xmx (max) and -Xms(min) memory to the same settings. The -Xss defaults to 4M which satisfies the stack size for most frameworks. Note that only altered entries show up in the file.


The letter at the end can be K, M, or G signifying Kilobytes, Megabytes, or Gigabytes.

For help with MapTool, TokenTool, or other RPTools products, please see the RPTools Forums or live chat on Discord.

MapTool Latest Release 1.7.0

You can download the new version of MapTool from the following links.

A JAR file version may be downloaded from the MapTool GitHub Repo and is only recommended for developers or other advanced users.

If you need help, please join our Discord Server. A list of all changes can be found in our Change Log

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