Mantra Distributed Rendering "No Code Generator Available" Error/Bug

[LucaScheller 61]

Hi, 
I am currently trying to use mantra in distributed rendering mode. (mantra -H machine1,machine2)

It all works as expected, but as soon as I connect something into a cached shader (for example a constant into the principled shader), the error “No Code Generator Available for opshader_path_xyz” pops up and it doesn't render at all anymore. It also happens with custom cached shader assets. All works well in non distributed rendering mode. If I unlock the asset, then it seems to work again since the asset is then "in the file", but this is unfortunately not useful in production.

Additional Info:
I am using windows and the “Force VEX Shader Embedding” checkbox is on. 

Has anyone experienced this error before? If no I'll submit a bug report.

Cheers,
Luca