I cloned the CryEngine Git repo and checked out the release branch. I ran download_sdks.exe, cry_cmake.exe and built the engine in VS 2017.

When I run my project I get a crash on startup:
The file in question: https://github.com/CRYTEK/CRYENGINE/blo ... s.cpp#L494

This is due to the rendering system missing its default assets. As we do not provide assets along with source code via GitHub you'll have to pull those in from the CRYENGINE Launcher installation. For that navigate to the CE Launcher engine installation that corresponds to the version of the Release branch that you're working in and copy the files in C:\Program Files (x86)\Crytek\CRYENGINE Launcher\Crytek\CRYENGINE_x.x\engine to the corresponding folder at the GitHub engine location. Note: The CRYENGINE Launcher assets are compatible with only the GitHub Release branch version of the engine.

Picking this up again - I followed the above and that solved that problem.

There is another issue now. I'm building in the 'Profile' configuration as recommended when I asked about this in Slack. The problem now is that I get a 'warning treated as error' message which prevents CrySystem from building.

23>d:\repositories\cryengine\cryengine-5.4.0\code\cryengine\crysystem\systeminit.cpp(274): error C2220: warning treated as error - no 'object' file generated
23>d:\repositories\cryengine\cryengine-5.4.0\code\cryengine\crysystem\systeminit.cpp(274): warning C4723: potential divide by 0

https://github.com/CRYTEK/CRYENGINE/blo ... t.cpp#L274

I got it to build by disabling the /WX flag

This is probably the intended divide by 0 error that's in the engine. You can find more information about it in this topic: viewtopic.php?f=64&t=4676&hilit=potential+divide+by