Big Empty file - how to reduce size

I have problem with huge file size. I’ve tried purge scene, even delete all object to find source of file size.
I have Rhino 5 and Vray on WIndows.
After deleting all scene elements, objects, layers, blocks and materials (from rhino and vray) it all looks like blank staring scene and it still save as big file.
So Vray Asset editor is empty - no materials, textures and so on.
But I found new window: V-ray\File Path Editor - and here I have a lot of matierialas. The problem is that there is no way to delete them.
Anyone know how to clean this materials?
Purge command didn’t work

try purging from the AssetEditor. If you don’t see anything in the AE, you should not see anything in the file path editor as well.
Check the Rhino material panel. Do you see materials there ?
Use the Rhino Purge command to delete some unused materials.
Rhino 5 uses a legacy material system, that every material is copied per object. And they may be left behind. if you have textures for those materials, they may still lay around

Thank you for your feedback.
V-Ray Asset Editor is empty - I used Purge option here (broomstick icon)
Material tab is empty (no filter so all should be visible) - I’ve delete all materials by hand
Also used Purge command in command line.
After all I still see materials in File Path Editor with texture assigned.

Interesting.
I see you use Rhino 5 and I guess V-Ray 4.20
Unfortunately this is out of support. I don’t have other ideas where the extra stuff comes from.
However if you send me the file, I can make a script, that you can run on your side to forcibly clean up all that stuff

That’s right Rhino 5 and V-ray 4.2.
Unfortunately due to NDA I can’t share any of my files.
Can you guide me where to find these script you mention to forcibly clean up all that stuff?

Hi
There is no panacea-like solution for the problem, since I have no idea what the problem is in a first place.
My intention was to write a script once I get your file, and see what needs purging. V-Ray 4 is out of support for quite some time, and unfortunately I can’t even build it, even less debug it.

Chaos offer a safe way to upload “sensitive” files. Would you consider contacting Chaos Support with this issue ? The guys there will let me know, once I have something from you

Ok, so I prepared a file in which I managed to reproduce the behavior and sent it to you in a private message.
In the scene I added the HDRI map in the GI, reflection and refraction slots and then removed it from every place.
In the asset editor everything is empty, but in the file path editor you can see the same map three times.
And it’s the same problem that I can’t clear this window