H18.0.287, Optix Denoser installed, Path entry is in the .env file and checked.
Whenever I switch to Karma the first time (no matter if Optix is enabled or not) I'm getting DSO errors for all the dlls in the Houdini dso/karma library. After that Karma renders fine.
Optix runs without issues in 17.5.

What am I missing? Is there anything else I need to configure?

Maybe try a daily build like 323.

make sure you haven't set HOUDINI_DSO_ERROR > 0 in your env. Setting it to zero (default) will supress the messages.

jsmack
make sure you haven't set HOUDINI_DSO_ERROR > 0 in your env. Setting it to zero (default) will suppress the messages.

But if it doesn't load properly suppressing the messages won't change that, would it? I usually have it a 2.

BabaJ
Maybe try a daily build like 323.

Same issue with 323.

OneBigTree

jsmack
make sure you haven't set HOUDINI_DSO_ERROR > 0 in your env. Setting it to zero (default) will suppress the messages.

But if it doesn't load properly suppressing the messages won't change that, would it? I usually have it a 2.

It loads properly. The messages are erroneous and can be ignored.

The DSO warnings are a known bug. Typically, the HOUDINI_DSO_ERROR variable is set when debugging, but should probably be left at 0 unless something is going wrong.

We will try to address the issue in a future build of Houdini/Karma.