UE4 Editor crashing on launch - just downloaded

I just downloaded and am trying to launch UE4.16.3 however the editor crashes everytime at 35%, any ideas would be appreciated.

Running on a 2017 iMac, 2.3 GHz Intel Core i5, Intel Iris Plus Graphics 640 1536 MB

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SEGV_MAPERR at 0x3

FGenericPlatformMisc::RaiseException(unsigned int) Address = 0x10015915b (filename not found) [in UE4Editor-Core.dylib]
FOutputDeviceMacError::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&) Address = 0x100354a2f (filename not found) [in UE4Editor-Core.dylib]
FOutputDevice::Logf(wchar_t const*, …) Address = 0x1004356cd (filename not found) [in UE4Editor-Core.dylib]
FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, …) Address = 0x10039b93e (filename not found) [in UE4Editor-Core.dylib]
FMemoryDerivedDataBackend::LoadCache(wchar_t const*) Address = 0x1188c18cf (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseBootCache(wchar_t const*, wchar_t const*, FString&) Address = 0x1188d07c8 (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseNode(wchar_t const*, FString const&, wchar_t const*, TMap >&) Address = 0x1188ccf7a (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseHierarchicalCache(wchar_t const*, wchar_t const*, FString const&, wchar_t const*, TMap >&) Address = 0x1188d0c76 (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseNode(wchar_t const*, FString const&, wchar_t const*, TMap >&) Address = 0x1188cd00a (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseAsyncPut(wchar_t const*, wchar_t const*, FString const&, wchar_t const*, TMap >&) Address = 0x1188d1374 (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseNode(wchar_t const*, FString const&, wchar_t const*, TMap >&) Address = 0x1188cd24b (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseKeyLength(wchar_t const*, wchar_t const*, FString const&, wchar_t const*, TMap >&) Address = 0x1188d1169 (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::ParseNode(wchar_t const*, FString const&, wchar_t const*, TMap >&) Address = 0x1188cd197 (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataBackendGraph::FDerivedDataBackendGraph() Address = 0x1188cbe2c (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataCache::FDerivedDataCache() Address = 0x1188df12b (filename not found) [in UE4Editor-DerivedDataCache.dylib]
InternalSingleton() Address = 0x1188beb39 (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataCacheModule::GetDDC() Address = 0x1188f57a9 (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FDerivedDataCacheModule::StartupModule() Address = 0x1188f571f (filename not found) [in UE4Editor-DerivedDataCache.dylib]
FModuleManager::LoadModuleWithFailureReason(FName, EModuleLoadResult&, bool) Address = 0x10049d05f (filename not found) [in UE4Editor-Core.dylib]
FModuleManager::LoadModule(FName, bool) Address = 0x10049bbfc (filename not found) [in UE4Editor-Core.dylib]
IDerivedDataCacheModule* FModuleManager::LoadModulePtr(FName) Address = 0x1004057d1 (filename not found) [in UE4Editor-Core.dylib]
GetDerivedDataCache() Address = 0x100405732 (filename not found) [in UE4Editor-Core.dylib]
GetDerivedDataCacheRef() Address = 0x100405845 (filename not found) [in UE4Editor-Core.dylib]
CompileGlobalShaderMap(EShaderPlatform, bool) Address = 0x102a7674b (filename not found) [in UE4Editor-Engine.dylib]
FEngineLoop::PreInit(wchar_t const*) Address = 0x1000599fa (filename not found) [in UE4Editor]
GuardedMain(wchar_t const*) Address = 0x10006bb71 (filename not found) [in UE4Editor]
-[UE4AppDelegate runGameThread:] Address = 0x10007a01a (filename not found) [in UE4Editor]
-[FCocoaGameThread main] Address = 0x100310346 (filename not found) [in UE4Editor-Core.dylib]
Unknown() Address = 0x7fffd15a88ad (filename not found) [in Foundation]
_pthread_body Address = 0x7fffe552693b (filename not found) [in libsystem_pthread.dylib]
_pthread_body Address = 0x7fffe5526887 (filename not found) [in libsystem_pthread.dylib]
thread_start Address = 0x7fffe552608d (filename not found) [in libsystem_pthread.dylib]

I have tried reinstalling etc, 4.17 works fine but I’m needing 16 due to my course using it