When getting a Vray render it shows this large flat rectangle which I have not purposely created. I try to click it on sketchup but it disappears so it cant be a real object i dont think…
It is made apparent in the Sketchup model around the plant warehouse extensions but isnt really there until I make a render. Weird stuff!
I’ve tried the classic restart etc. Has anyone seen this before? Unfortunatley I can only show one picture
The picture you posted suggests that the plants have a 2D representation, possibly as a face painted with a PNG image. If the face has its back side facing upwards it might lead to V-ray rendering it with a default material. Impossible to say for sure without the SKP file. Tags is what Layers was renamed to in the 2020 version of SketchUp.
I think the issue is that you have a hidden face that turns up in V-ray. V-ray is in my experience not good at inventing geometry that is not there. You showed an image that suggests that it is something inside your plant components (were they downloaded from the 3D Warehouse?)
Another possibility would be the SketchUp ground plane if your floor level coincides with it and tha actual “ground” is below it, but that should show as an infinite plane.
Until we see the actual SKP file we are just guessing.