This guide will show how to fix "Pure server: file [GAME]\pak01_001.vpk does not match the server's file"
Go to "CDRIVE" and doubleclick
Then Select "ProgramFiles(x86)"
Next select "Steam"
Next Click "Steamapps"
Then Select "Common"
Next Select "Counterstrike Global Offensive"
Then Select "CSGO"
Scroll down and Delete all files with the letters "pak" including the two "pakxv_lowviolence" files and "pure_server_whitelist"
Next you must verify integrity of game cache, which will install all missing files.
Right Click steam icon on bottom right of your desktop where running programs are shown. Select library.
Right click CSGO and Select Properties
Next Click the "Local Files" tab on top
Next click "Verify Integrity of Game Cache"
This will take a little time to install the corrupt and missing files. I hope this helped you! Cheers!
-Jason