Maya Hydra Preview Viewport Options Missing From Renderer Tab

[Brithub77]

Describe the bug
Plugin mayaHydra.mll fails to load correctly.

Steps to reproduce
Steps to reproduce the behavior:
Open Plug-in Manager.
Reload mayaHydra.mll.
See Script Editor.
Look for error below:

// Error: file: C:/Program Files/Autodesk/Maya2026/scripts/others/pluginWin.mel line 316: (mayaHydra)

Specs (if applicable):
Windows 11
Maya 2026.3

[santosd]

Hello @Brithub77, thank you for reporting this issue. Wondering what version of Maya USD and What version of Hydra it is that your are using? Could you try downloading the latest from here:
https://github.com/Autodesk/maya-usd/releases/tag/v0.34.6
and try to load the plugin again.
If that doesn't work, are you using a custom build of Maya USD or Maya Hydra?
Is this a reload of the plug-in? Does the plug-in work on initial load?

[Brithub77]

I'm the using the versions that come with Maya 2026.3. Nothing custom. And the plugin loads but gives the error I mentioned above.

[Brithub77]

By the way, I already tried reinstalling Maya 2026.3, downgrading to 2026.2, and installing a lower MayaUSD version. Those options did nothing for me. I even upgraded my GPU, and still nothing has changed.

I also reset my preferences and uninstalled several plugins I was using before, nothing changed.
I modified my environment paths and Python paths, nothing changed.
I changed the rendering API to DirectX then back to OpenGL, nothing changed.
I downgraded Arnold to older versions I was using before, nothing changed.
I unloaded other plugins, nothing changed.
I went as far as to fully uninstall Maya 2026.3 as a last resort. To my disbelief, nothing changed.

It doesn't load in other versions of Maya either.
It used to load just fine in early December.

[lilike-adsk]

Have a try with mel script getenv "MAYA_MODULE_PATH"; to check if the module path is messed up by other stuff.

[santosd]

Thanks @Brithub77 for all of that info. I was going to suggest what @lilike-adsk said as well. If you run that MEL, then it will throw a bunch of paths where Maya is looking for .mod files. If you have a mayausd.mod file or another .mod file that points to a different location to pickup the MayaUSD and MayaHydra it could interfere the version you have installed or are trying to run. These mod files are not removed on and uninstall or prefs reset.

[Brithub77]

I checked and there are no excess .mod files. I tried look at the module path before but the same issue kept occurring.

[santosd]

Is Maya Hydra the only plugin that is failing to load for you?
In the Plug-in Manager what is the Path from which the Maya Hydra plugin is loading?
You can also query the path: pluginInfo -q -path "mayaHydra";

It seems to me like you have done everything to ensure that the install is correct so I don't think the issue has to do with your installed files. It seems to me that what could be happening is that some sort DLL search path conflict. Do you have other DCCs that could be interfering due to a set PATH env var or maybe a PYTHON_PATH.

[Brithub77]

Yes, it's the same path where you have it installed.

I do have many other plugins installed but don't feel comfortable uninstalling them.