Unity out of window handles/UI stops responding.

Every 2 or 3 minutes, the entire Unity editor’s UI stops working and I get the following error on the bottom status line:

“Error displaying dialog: The current process has used all of its system allowance of handles for Window Manager objects.”

When this happens, clicking on any menu or control in the Unity editor does nothing, yet I can minimize, move, and drag the entire application window.

I have a completely blank project & scene and no other applications open.

How can I fix this?

Did you ever figure this out?

I’ve also noticed this behavior. It appears that Unity is leaking USER Objects and hitting the process limit of 10k, but I haven’t yet been able to figure out why. Once it hits this limit, it can no longer display dropdown menus or dialogs.

To view this behavior, go to your Windows Task Manager and Select View->Select Columns and check “USER Objects.”

On one machine, I don’t have this problem at all. On another, I easily reach the 10k limit within a few minutes, playing around with simple demo projects or relatively empty scenes.

Some possible factors that may be contributing to the problem:

  • I am using multiplicity
  • I am running the Asset Server on the same machine that is having problems with the Unity client
  • I have reproduced this problem with both version 3.5 and 3.5.5f2

If you hit this, see my reply to http://forum.unity3d.com/threads/unity-compatibility-with-multiplicity.96618/