Tech Note: Installed Build Generation Fails with Visual Studio 2017 in 4.26.0

Jan 20, 2021.Knowledge


The 4.26.0 release fails to create an installed build correctly if you only have VS2017 installed. This is due to a warning that occurs in VS2017, but not VS2019, which is treated as an error in the installed build generation, causing the failure. The warning is due to some compilers ( IE: VS2017 ) not correctly picking up a PRAGMA_… definition in EditorEngine.h and a few other files, unless they’re at file scope.

Potential Impact:

Moderate: This will affect anyone on 4.26.0 trying to generate an installed build through BuildGraph with only VS2017 and its toolchains installed.


This should be fixed as of 4.26.1, but if you need it before that, the fixes are in //UE4/Release-4.26/ stream. Integrating CL 15004310 followed by 15015879 addresses the warning that’s generated.