When upgrading any project from 5.4 to 5.5 and then trying to bake lighting only, the baking fails with no useful errors:
MapCheck: Map check complete: 0 Error(s), 0 Warning(s), took 0,035ms to complete.
LogSlate: Took 0.000073 seconds to synchronously load lazily loaded font '../../../Engine/Content/Slate/Fonts/Roboto-Regular.ttf' (155K)
LogSlate: Took 0.000358 seconds to synchronously load lazily loaded font '../../../Engine/Content/Slate/Fonts/Roboto-BoldCondensed.ttf' (158K)
LogStaticLightingSystem: Running Lightmass w/ ImmediateImport mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ ImmediateProcess mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ Sorting mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ Mapping paddings ENABLED
LogStaticLightingSystem: Running Lightmass w/ Mapping debug paddings DISABLED
LogEditorBuildUtils: Build time 0:00
LogUObjectHash: Compacting FUObjectHashTables data took 0.22ms
LogStaticLightingSystem: Warning: Failed to build lighting!!! Lighting build failed.
DumpUnbuiltLightIteractions
Lights with unbuilt interactions: 18
On MacOS