Meta Data
Have you customized or edited meta data and similar configuration files?
There are so many files that can be customized in GTA 5. There are settings for essentially all components from weather, to time, to populations, and of course all the files relating to vehicles and peds.
We can't cover all these files, most of which are just plain text, or extracted to text for editing purposes, so we will just provide some words of caution.
As you are more experienced with Open IV's editor, you will likely customize GTA 5 yourself. Making edits to files such as vehicles.meta, handling.meta, converting replace vehicles to addons, adding or replacing textures, renaming files, and consolidating dlcs into one rpf - all of these are part of the modding adventure.
Beware that duplicate file and folder names exist throughout both the Games and Mod folders. Always ensure you are editing the proper file or folder from the proper path. For example dlclist.xml can also be found in components.rpf and that's not the file you want to edit. You want the one in mods, update, update.rpf.
All of these modding and customization actions require attention to detail. Mistakes will lead to possible issues which is why keeping track of changes will help troubleshoot if something goes wrong. And of course backup!
A note about Dlclist.xml
This is the most frequently edited file by GTA 5 modders. New addons must be added to this file, with the correct folder names and correct syntax. It's always best to copy a working dlclist entry and then edit it. Syntax errors with this file are common reasons for addons not spawning.
Make sure you have opening and closing tags for example. Note: OIV installers can delete this file and replace it with an outdated one.
A note about gameconfig.xml
Unless you understand exactly what you're changing, leave the default values for essential files such as gameconfig.xml and the heap limit adjuster. Increasing these limits is no guarantee at all that your game will allow you to install more mods. On the contrary, they could lead you to believe that they will allow more mods than your hardware can support - inevitably ending in a crash.