Error while starting forge instances = v1.7.2

Due to the evolutions of technology, it's really hard to maintain backward compatibility for all versions. Our launcher is new and it has been written from the ground up using no legacy code or technologies (unlike many other launchers).

If you have issues running some old versions of Minecraft, try installing (on top of the one you already have installed) an older version of Java (Java 7 for example..).

Then, in the specific instance you have problem with, open its settings and select that version of Java.

If you're running Forge #965 for Minecraft 1.6.4, Forge #1121 / #1147 for Minecraft 1.7.2 or Forge #1208 for Minecraft 1.7.10, please refer to this guide.

If you still can't solve your issue, please, reach us on Discord. Our community will be there to help!