The version of ESX you’re using and the version he dev’d this on are most likely different in how they call locales. There is a fix for this, but I’ve forgotten what it is. You’re best bet might just to directly edit the messages/text instead of using locales for now.
As for your other comment,
Make sure the maV_core is started AFTER the warehouse script
OR
just go to his core and look for where he calls for the ESX Object and insert export there.
Free releases: Releases that are released for free must contain a direct download and may not be Escrow protected, you may include a Tebex link but it may not be the only download.
In the editable area, you can edit the inventory according to which inventory you are using. But this is my mistake, I will adapt it for a few inventories soon.