UE-47259 error occurring on 4.18.3

We are getting the following error on a Mac (High Sierra, UE4.18) attempting to load a project last used in 4.9. The level is a terrain with placed foliage, quite large (several kilometers), using KiteDemo assets. The project converted to 4.18 after changes to the .cs files but now aborts when we attempt to load it. The error message from the log is:

[2018.05.26-22.10.04:403][ 0]LogStaticMesh: Allocated 507x174x115 distance field atlas = 19.4Mb, with 76 objects containing 8.9Mb backing data
[2018.05.26-22.10.04:830][ 0]LogMac: Error: appError called: Assertion failed: Assertion failed: ShaderRef != NULL && *ShaderRef != nullptr [File:Runtime/ShaderCore/Public/Shader.h] [Line: 1448]
Failed to find shader type FUploadObjectsToBufferCS in Platform SF_METAL_SM5

[2018.05.26-22.10.04:841][ 0]LogMac: === Critical error: ===
SIGSEGV: invalid attempt to access memory at address 0x3

This error matches the issue reported fixed in UE-47259 as of 4.18. The project can’t be opened in old versions of UE, because none will work on High Sierra, but we would like to recover the map that seems to be causing this for our game.

We would like to determine if there is a work around for this, or if the problem can be reopened if it suggests that it wasn’t actually corrected.

Thanks for your time.

The solution to this was to move to 4.19.2. Apparently it wasn’t fixed in the 4.18 release as the UE-47259 issue stated. It loads in 4.19.