Ok, yes this has been answered before, but no problem, I'll explain it to you.

The OOM ( out of memory) message comes because of the texture maps that Vue has to load in your RAM for your Poser figures. Poser relies on hi res textures for its figures. Check in your runtimes the size of the images, they generally are 2048x2048, if not higher.

It is not recommended to have more than 3 figures in a scene (I'm not talking about ecosystem figures, just "real" ones.)

A workaround would be to: load them in separate layers, and hide the layers you are not currently working on, and make several render passes and composite in a paint program.

Another workaround is to buy SkinVue2 at Cornucopia3D, it's a Python script that swaps Poser textures for procedural Vue materials, and doesn't need much resources, and looks very realsitic.

Or create yourself in a paint program  a lower resolution of  your Poser figure texture maps.