Found it.
https://github.com/gildor2/UEViewer/commit/bda2f3ff2bbc05f217ba6b3db42301a3012cd2fe#diff-2493c839787b641f8462e4b351245f93b17d21655609967dc61823ecf9e5ea1a - this is where it stopped working
If you're looking into this, would please also look into an issue that's been there forever:
ERROR: Memory: bad allocation size -170186172 bytes
appMalloc:size=-170186172 (total=95 Mbytes) <- FArray::Empty:-1087924005 x 12 <- TArray::SerializeSimple <- SerializeBulkArray <- FStaticMeshVertexStream3<< <- FStaticMeshLODModel3<< <- TArray::Serialize:0/1 <- UStaticMesh3::Serialize <- LoadObject:StaticMesh3'BGND_KR_IL_Tunnel_ScriptAssets.KR_IL_TN_EggSac1Chest_St', pos=75BA16, ver=677/157, game=mk <- UObject::EndLoad <- LoadWholePackage:BGND_KR_IL_Tunnel_ScriptAssets.xxx <- ExportPackages <- CUmodelApp::ShowPackageUI <- Main:umodel_build=1292
I can upload sample files if need be(tell me on which file-sharing site)