Crash on startup, exception code 0xc000007b

Generally, the 0xc000007b error is caused by .Net or VC problems.

Try repairing the 2015-2019 VC redistributable package: in the Control Panel, Programs and Features, right click the MS VC++ 2015-2019 redistributable entries (32 bit and 64) and select Uninstall and then Repair. If you still get the error after that, right click again and uninstall, reboot and reinstall.

C:\Program Files (x86)\Steam\SteamApps\common\Steamworks Shared\_CommonRedist\
C:\Program Files (x86)\GalaxyClient\Dependencies\__redist
or https://support.microsoft.com/en-ca/help/2977003/the-latest-supported-visual-c-downloads

If that still doesn't help, if you are getting any missing dll errors when starting from the executable, try copying the relevant dll files from either the C:\Windows\System32 or C:\Windows\SysWOW64 folders into the applicable bin folder, and retry starting the game. There may be other dll errors, but if it is only a small number, copying them into the install folder may bypass whatever the problem is, and get the game to start.

Tom's Hardware has a guide for this error (written for Win 7/8, but it should mostly be applicable to Win 10, as well). 

A post in a Win 10 forum reported fixing this by manually replacing some dll files (as recommended in the guide above, as a last resort). 

One person with this error reported that uninstalling Skype fixed it and (after installing the Microsoft Universal C Runtime to fix a dll error) got the game working. He had used the Dependency Walker program to look at the D:OS 2 executable, and found that for some reason the system was trying to access dll files in the Skype folder, rather than the system folders. A couple of other people with this error tried that, but found no such issues, though.
To check, after starting the program and opening the EoCApp.exe game executable, right click the window and select 'show full paths' (or hit F9), then check the list of dlls; most should be in C:\Windows\System32, possibly a video driver folder under c:\Windows, or the game's install folder.

Try checking your system files:
- click Start, type cmd into the search box, right click Command Prompt and select run as administrator.
- type the following command and hit Enter
sfc /scannow
When that is done, type exit and hit Enter, then reboot your computer.
For more details, see: https://support.microsoft.com/en-ca/kb/929833

For the launcher, if it is not starting through Steam / Galaxy, try exiting out of the client and starting it from the '..\SteamApps\common\Divinity Original Sin 2\bin\SupportTool.exe' executable.

If the launcher doesn't start from the executable, try deleting the config.xml file in the '..\Divinity Original Sin 2\bin' folder, as well as 'C:\Users\<UserName>\AppData\Local\LarianLauncher' (copy and paste %LocalAppData%\LarianLauncher into Windows Explorer to quickly open that folder).

If that doesn't help, try reinstalling .Net Framework 4.
C:\Program Files (x86)\Steam\SteamApps\common\Steamworks Shared\_CommonRedist\DotNet
C:\Program Files (x86)\GalaxyClient\Dependencies\__redist\dotNet4
or https://www.microsoft.com/net/download/dotnet-framework-runtime

If that doesn't at least get the launcher starting from the executable, there is also a Microsoft .NET Framework Repair Tool, or if that doesn't help, Cleanup Tool.