Fix Modrinth App: Could Not Create the Java Virtual Machine | NodeFlux.eu Docs

Troubleshoot the Modrinth App JVM launcher error by checking invalid Java options, the selected Java installation, and whether the failure is on your computer or the server. NodeFlux documentation for free Minecraft, Node.js and application hosting.

Steps

  1. First identify where the error appears. If Modrinth shows it while launching Minecraft on your computer, these steps apply to your client; they do not change the Java runtime used by a NodeFlux server.
  2. On Windows, open the Environment Variables settings and check both your user variables and system variables for _JAVA_OPTIONS. Modrinth documents invalid values in this variable as a cause of JVM launcher failures.
  3. If _JAVA_OPTIONS is present and you do not intentionally need it, remove that variable only. Do not delete other Java variables or paste unknown memory flags from a guide.
  4. Sign out of Windows and sign back in so the environment change is applied, then retry the same Modrinth profile.
  5. If the error continues, open Modrinth App Settings > Java installations and use the app's recommended Java installations. Confirm the selected profile uses a compatible installation, then restart the app.
  6. For Minecraft 1.16.5 or older, Modrinth notes that an out-of-memory message can be caused by using 32-bit Java; use a 64-bit installation for those versions.
  7. If Minecraft still will not launch, note the exact error and share the Modrinth log with support. If instead the error is in the NodeFlux server console, check that server's startup log and selected Java egg; changing your PC's _JAVA_OPTIONS will not fix a server-side runtime problem.

Notes