Migrating project from 4.23 to 4.24 - ICU data directory was not discovered

While building my project under 4.24 (moving from 4.23), I’m now encountering this error on project startup:

Fatal error: [File:C:/Path/To/UE4_24/Engine/Source/Runtime/Core/Private/Internationalization/ICUInternationalization.cpp] [Line: 153]
ICU data directory was not discovered:
../../../MyPlugin/Content/Internationalization
../../../Engine/Content/Internationalization

Along with an assert failure here:

Assertion failed: FPaths::DirectoryExists(RealShaderDirectory) [File:C:/Path/To/UE4_24/Engine/Source/Runtime/RenderCore/Private/ShaderCore.cpp] [Line: 1243] 

My UE_ENGINE_DIRECTORY define matches the path of the correct engine build on my machine, and the directories in question exist and are populated. The engine launches when built on its own, and will build and launch a fresh project, but not this migrated one. If there anything I can do to fix this issue and continue working on my project?

This is on Win64, and using BuildEnvironment = TargetBuildEnvironment.Unique (for C++17 support).