Error occurred during initialization of VM. Could not reserve enough space for object heap

Last checked 2026-10-26 · 3 fixes · reviewed answer

TL;DRMinecraft cannot start because the Java virtual machine cannot allocate the requested amount of memory for its heap space.

Most likely cause: Minecraft launcher is set to use more RAM than the computer has available

Try first: Close other applications before launching Minecraft

Likely causes

Minecraft launcher is set to use more RAM than the computer has availablemost likely
Other programs are using most of the system's memorypossible
32-bit Java is installed on a 64-bit system and cannot address enough memoryless likely

Safest first: SafeChanges settingsDangerous

Close other applications before launching MinecraftSafe

Shut down web browsers, video players, and other memory-heavy programs to free up system RAM.
Lower the allocated RAM in the Minecraft launcherChanges settings

Open the Minecraft Launcher, go to Installations, edit your installation, and reduce the JVM arguments value for -Xmx to a lower number such as 2G or 4G.
Switch to a 64-bit Java runtime if using 32-bitChanges settings

In the Minecraft Launcher, select a 64-bit Java executable under the installation settings if the option is available.

Check the total physical RAM in Task Manager and try setting the -Xmx value to half of that amount.

See a technician if your computer has less than 4 GB of RAM or if the error continues after trying lower memory settings.

What does Error occurred during initialization of VM. Could not reserve enough space for object heap mean?: Minecraft cannot start because the Java virtual machine cannot allocate the requested amount of memory for its heap space.
What causes Error occurred during initialization of VM. Could not reserve enough space for object heap?: Minecraft launcher is set to use more RAM than the computer has available. (most likely) Other programs are using most of the system's memory. (possible) 32-bit Java is installed on a 64-bit system and cannot address enough memory. (less likely)
How do I fix Error occurred during initialization of VM. Could not reserve enough space for object heap?: Try these in order, safest first: 1. Close other applications before launching Minecraft. 2. Lower the allocated RAM in the Minecraft launcher. 3. Switch to a 64-bit Java runtime if using 32-bit.
What if that didn't fix it?: Check the total physical RAM in Task Manager and try setting the -Xmx value to half of that amount.
When should I see a technician?: See a technician if your computer has less than 4 GB of RAM or if the error continues after trying lower memory settings.