Build Fails with Error C3646 'Platform': unknown override specifier error when updating to UE5.2

Development Programming & Scripting C++
, ,
1

I was trying to update my project to UE5.21, but one of my modules failed to compile with error : Severity Code Description Project File Line Suppression State
Error C3646 ‘Platform’: unknown override specifier MigJourney C:\Program Files\Epic Games\UE_5.2\Engine\Source\Runtime\RHI\Public\DataDrivenShaderPlatformInfo.h 156

to put you in context, the said module uses slats, for a async loading screen.
it seems that slats and RHIDefinitions conflict.
if you face the same error just add include “RHIDefinitions.h” before any slate related header and you should be good to go.

I hope though this will be automatically prevented in future releases, as it is very frustrating and basically no documentations available to help in the debugging process.

2

It’s a bit of an odd question but after having the same issue, your post was a life saver. How were you actually able to track down the issue to this particular scenario?

3

if i remember correctly, i was using android studio back then. and i was getting an error about some type not being defined.
i did then checked up the header files and the type was defined there so after some trial and error i figured out the it must me order issue may be some macro “def / undef” issue.
reordering the headers solved that.

in these kind of scenarios you really need luck on your side :hugs: