The case of the hrender that failed to start AdskLicensingAgent

Or, “things that happen when you use single-user licensing on a render node” 😉

In this case, a Houdini command-line render with Arnold (HtoA) failed because the AdskLicensingAgent failed to start.

This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: minimal, offscreen, webgl, windows.


After AdskLicensingAgent crashed, the render would continue, but license authorization would fail:

00:00:00   148MB         | authorizing with license manager: user ...
00:00:31   153MB WARNING | rendering with watermarks because of failed authorization:
00:00:31   153MB         |  [clm.v2] timeout before callback was called

Using Process Monitor, I saw (as expected) that the problem was that the AdskLicensingAgent was loading Qt platform plugins from Houdini:

The solution? Set QT_QPA_PLATFORM_PLUGIN_PATH to point to the AdskLicensingAgent\platforms folder.

set QT_QPA_PLATFORM_PLUGIN_PATH=C:\Program Files (x86)\Common Files\Autodesk Shared\AdskLicensing\Current\AdskLicensingAgent\platforms