engine error

[The_Gl!tch.exe]

I'm trying to test my new map on sv_pure 2 but I get an engine error and the game crashes.
I've created LDR cubemaps with this tutorial: https://tf2maps.net/threads/tutorial-cubemaps-and-how-to-make-them.25699/
I've also packed everything with VIDE (there is no nav file (which usually cause crashes))

Is there something I've missed causing the crash? pls help

 

[DrSquishy]

What is the engine error you are getting

 

[The_Gl!tch.exe]

What is the engine error you are getting

It says: failed to lock vertex buffer in CMeshDX8::LockVertexBuffer: nVertexCount=2204, nFirstVertex=0

 

[The_Gl!tch.exe]

So I've tried deleting the bsp file and starting over again but I still get this error
https://i.imgur.com/oB8GsMa.jpg
I still don't know what causes this