Common Causes for Game Failures
There are so many factors or combinations of factors which is why patience and a step by step approach is required. The following is a list of common issues, however this list is in no way complete as there are too many different setups out there involving PC hardware, software, game settings, installed mods, mod settings, etc.
PC hardware (GPU, CPU, System RAM, available storage/HDD). Your system may not be powerful enough to meet requirements for modding. Particularly true for laptops. For example, if you are running Windows 7 on a laptop with integrated graphics go real easy on the type and quantity of mods you install. If you can't upgrade your components or the PC itself, again add mods one by one and see if you can handle them before adding others.
PC Software such as video or other PC drivers. Make sure drivers are up to date, particularly if you are experiencing texture issues like flickering, tearing, texture losses, or low FPS. Set graphic settings to default or lower if necessary. DirectX and NET Framework versions can cause issues as well, so keep them updated.
GTA5 Version (Steam, Epic, Retail) not updated or using warez version. GTA5 should be uncracked and kept updated with most recent mods when available. Support for cracked versions is not available on this site. Installing more than one copy of GTA 5 on the same PC can cause conflicts and crashes.
Scripthook V (latest version) not properly installed. Must be installed in root folder with GTA5.exe (same location for asi mods). Extract the package, remove ScriptHookV.dll and dinput8.dll from the bin folder, and place them in the root folder. You don't need and don't want the trainer file. Don't confuse scripthook with scripthook dot net. See point 8.
OpenIV not properly installed, use its default settings and you shouldn't have any issues.
Gameconfig.xml missing this mod or improperly installed. You need OpenIV to install it. Use base settings to start. Don't modify this file based on some random post you read. It should work fine even with 300+ cars or peds installed right out of the box. Note: OIV installers can delete this file and replace it with an outdated one. The vanilla version of gameconfig.xml is not suited to support modding.
Heap and packfile limit adjusters. Both these essential asi files go in root folder with GTA5.exe
Script Hook V .NET, NativeUI, and LemonUI. These important and often required mods could be missing or not installed properly. Follow instructions carefully. These are not required by all mods. The dot net files go in the root folder but most .dll files go in the scripts folder. Additionally, updates to Script Hook V .NET and LemonUI could break scripts as they are not always backwards compatible. NativeUI and LemonUI go in scripts folder.
Mod File Structure. Ensure all folders are correctly implemented. There are YT videos which actually have the wrong structure. For example update.rpf in wrong folder. You also may need to set folder permissions given many mods will write or save information on your PC. Watch the videos in this thread if unsure or to confirm proper setup.
Dlclist.xml. New addons must be added to this file, with the correct folder names and correct syntax. Best to copy a working entry and edit it. Make sure you have opening and closing tags for example. Note: OIV installers can delete this file and replace it with an outdated one.
Improper Mod Installation in the wrong folder/wrong path, or missing mod requirements. Note: OIVs are better installed manually. Caution is required for replace mods as they often involve more than one path/location. Always use a Mods folder. The root folder is where your .asi and many .dll files are installed (e.g. dinput8.dll, ScriptHookV.dll) but generally speaking the .dll from script mods will be in the scripts folder. Proper Installation of Tools and Script Mods
Quantity of Mods. Too many mods installed, particularly high polygon count vehicles or massive maps/MLOs. GTA5 was not designed for modding. Push too far, too much and you will crash. You can mitigate issues with properly configured gameconfig, visual settings, and the proper hardware.
Currency. Outdated or defective mods may no longer work with new versions of GTA5 or other mods. Old mods do die, they can expire like food.
Corrupt or missing game files. This may happen with or without meaningful error messages. The save game file may also be corrupted, particularly if autosaving during a crash. A verify integrity (or reinstall) will fix most issues, but not corrupt save files, so backup. If necessary start a new game.
Customizing mods. As you are more experienced, you will likely customize yourself. Making edits to files such as handling.meta, converting replace vehicles to addons, adding or replacing textures, renaming files, and consolidating dlcs into one rpf. All of these 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.
Reinstalling. Doing a complete reinstall rather than a verify integrity is not usually necessary. Many users are under the wrong impression that this will fix broken mods as well. A reinstall only impacts GTA5 files, it does nothing to your saved games or mod files. Which is why a clean reinstall is the way to go when all else fails. This means uninstalling and then manually deleting any remaining files and folders in documents as if game never existed.
Editing Wrong File. 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 common.rpf and that's not the file you want to edit. You want the one in mods, update, update.rpf.
Game Updates. These are notorious for breaking games completely or specific mods. See this Recovering from a game update for more info. Remember that Rockstar updates and patches don't break GTA5, they only break modded GTA5.
OIV Installations. As mentioned in points 6,10, and 11, automatic installers such as OIVs can replace new files with outdated ones. Avoid them if possible, do a manual installation.
Update.rpf updates. Copying a new version of Update.rpf after a Rockstar game update, from the game folder to your mods folder, either manually or as prompted to do so by OpenIV will result in gameconfig.xml, dlclist.xml, and any of your customizations to be deleted and replaced, causing potential crashes and preventing addons from loading if you don't replace these files from backups. Some users have fixed their issues by also copying over Update2.rpf which was introduced in April 2022.
Bad Advice. Be wary of morons on YouTube who claim 100% fixes for GTA5 crashes. Particularly the ones advising you wrongly to replace dinput8.dll with the one from the Windows system32 folder. It won't load any mods, giving you a false impression game is fixed.
If your game doesn't load or run properly with a fresh install and without any mods installed, consult the official Rockstar troubleshooting guide.