file.Read not working?

I tried the example here:
[lua]print( file.Read(“materials/vgui/sandbox.vmt”, true) )[/lua]

and it says:

[addons/saver/lua/autorun/test.lua:2] attempt to call field ‘Read’ (a nil value)

???

You’re using the file variable name probably somewhere else. Show us the code around it, and make sure you’re not doing
local file = something or having it in the parameters of a function.