Packaging keeps trying to nativize Blueprints

While trying to package my game for Steam, I’ve been encountering really strange errors that don’t make any sense. It started with Fonts going missing (but existing on disk), materials that won’t compile on OpenGL due to ‘step’ not being a valid function (I don’t even understand that one), Blueprints constantly referring to /Engine/Transient and finally it trying to nativize Blueprints - while that option isn’t even active!

How do I even package a game if it doesn’t follow any of the configuration options i give it?

Log:

Cmd: OBJ SAVEPACKAGE PACKAGE="/Game/Levels/Game" FILE="../../../../../../Projects/UnrealEngine/Sirius-Online/Saved/Autosaves/Game/Levels/UEDPCGame.umap" SILENT=true AUTOSAVING=true KEEPDIRTY=true
LogSavePackage: Save=38.31ms
LogSavePackage: Moving '../../../../../../Projects/UnrealEngine/Sirius-Online/Saved/UEDPCGameC45A415B4352DFA522CC72B4A80D712C.tmp' to '../../../../../../Projects/UnrealEngine/Sirius-Online/Saved/Autosaves/Game/Levels/UEDPCGame.umap'
LogSavePackage:Display: Finished SavePackage ../../../../../../Projects/UnrealEngine/Sirius-Online/Saved/Autosaves/Game/Levels/UEDPCGame.umap
LogEditorTransaction: Undo Spawn Play From Here Start
UATHelper: Packaging (Windows (64-bit)): Running AutomationTool...
UATHelper: Packaging (Windows (64-bit)): Automation.ParseCommandLine: Parsing command line: -ScriptsForProject=C:/Projects/UnrealEngine/Sirius-Online/Sirius.uproject BuildCookRun -nocompile -nocompileeditor -installed -nop4 -project=C:/Projects/UnrealEngine/Sirius-Online/Sirius.uproject -cook -stage -archive -archivedirectory=C:/Projects/UnrealEngine/Sirius-
Online/#Build -package -clientconfig=Development -ue4exe=UE4Editor-Cmd.exe -prereqs -targetplatform=Win64 -build -CrashReporter -utf8output
UATHelper: Packaging (Windows (64-bit)): Automation.Process: Setting up command environment.
UATHelper: Packaging (Windows (64-bit)): BuildCookRun.SetupParams: Setting up ProjectParams for C:\Projects\UnrealEngine\Sirius-Online\Sirius.uproject
UATHelper: Packaging (Windows (64-bit)): Project.Build: ********** BUILD COMMAND STARTED **********
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files (x86)\Epic Games\4.13\Engine\Binaries\DotNET\UnrealBuildTool.exe Sirius Win64 Development -Project=C:\Projects\UnrealEngine\Sirius-Online\Sirius.uproject  C:\Projects\UnrealEngine\Sirius-Online\Sirius.uproject  -remoteini="C:\Projects\UnrealEngine\Sirius-Online" -noxge -generate
manifest -NoHotReload
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 1,4946903s to run UnrealBuildTool.exe, ExitCode=0
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files (x86)\Epic Games\4.13\Engine\Binaries\DotNET\UnrealBuildTool.exe Sirius Win64 Development -Project=C:\Projects\UnrealEngine\Sirius-Online\Sirius.uproject  C:\Projects\UnrealEngine\Sirius-Online\Sirius.uproject  -remoteini="C:\Projects\UnrealEngine\Sirius-Online" -noxge -NoHotRel
oad -ignorejunk
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: Performing 3 actions (3 in parallel)
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: BP_SkyBox__pf1017381123.cpp
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: C:\Projects\UnrealEngine\Sirius-Online\Intermediate\WindowsNoEditor\NativizedAssets\Source\NativizedAssets\Private\BP_SkyBox__pf1017381123.cpp(240): error C4146: unary minus operator applied to unsigned type, result still unsigned
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: C:\Projects\UnrealEngine\Sirius-Online\Intermediate\WindowsNoEditor\NativizedAssets\Source\NativizedAssets\Private\BP_SkyBox__pf1017381123.cpp(261): error C4146: unary minus operator applied to unsigned type, result still unsigned
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: C:\Projects\UnrealEngine\Sirius-Online\Intermediate\WindowsNoEditor\NativizedAssets\Source\NativizedAssets\Private\BP_SkyBox__pf1017381123.cpp(283): error C4146: unary minus operator applied to unsigned type, result still unsigned
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: C:\Projects\UnrealEngine\Sirius-Online\Intermediate\WindowsNoEditor\NativizedAssets\Source\NativizedAssets\Private\BP_SkyBox__pf1017381123.cpp(305): error C4146: unary minus operator applied to unsigned type, result still unsigned
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: C:\Projects\UnrealEngine\Sirius-Online\Intermediate\WindowsNoEditor\NativizedAssets\Source\NativizedAssets\Private\BP_SkyBox__pf1017381123.cpp(327): error C4146: unary minus operator applied to unsigned type, result still unsigned
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: C:\Projects\UnrealEngine\Sirius-Online\Intermediate\WindowsNoEditor\NativizedAssets\Source\NativizedAssets\Private\BP_SkyBox__pf1017381123.cpp(349): error C4146: unary minus operator applied to unsigned type, result still unsigned
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: ERROR: UBT ERROR: Failed to produce item: C:\Projects\UnrealEngine\Sirius-Online\Intermediate\WindowsNoEditor\NativizedAssets\Binaries\Win64\UE4-NativizedAssets.lib
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: Total build time: 8,85 seconds
UATHelper: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 9,0206617s to run UnrealBuildTool.exe, ExitCode=5
UATHelper: Packaging (Windows (64-bit)): Program.Main: ERROR: AutomationTool terminated with exception: AutomationTool.CommandUtils+CommandFailedException: Command failed (Result:5): C:\Program Files (x86)\Epic Games\4.13\Engine\Binaries\DotNET\UnrealBuildTool.exe Sirius Win64 Development -Project=C:\Projects\UnrealEngine\Sirius-Online\Sirius.uproject  C:\Pr
ojects\UnrealEngine\Sirius-Online\Sirius.uproject  -remoteini="C:\Projects\UnrealEngine\Sirius-Online" -noxge -NoHotReload -ignorejunk. See logfile for details: 'UnrealBuildTool-2016.10.14-01.1
UATHelper: Packaging (Windows (64-bit)): 3.39.txt' 
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.CommandUtils.RunAndLog(String App, String CommandLine, String Logfile, Int32 MaxSuccessCode, String Input, ERunOptions Options, Dictionary`2 EnvVars, SpewFilterCallbackType SpewFilterCallback)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.CommandUtils.RunAndLog(CommandEnvironment Env, String App, String CommandLine, String LogName, Int32 MaxSuccessCode, String Input, ERunOptions Options, Dictionary`2 EnvVars, SpewFilterCallbackType SpewFilterCallback)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.CommandUtils.RunUBT(CommandEnvironment Env, String UBTExecutable, String CommandLine, String LogName, Dictionary`2 EnvVars)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.CommandUtils.RunUBT(CommandEnvironment Env, String UBTExecutable, FileReference Project, String Target, String Platform, String Config, String AdditionalArgs, String LogName, Dictionary`2 EnvVars)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.UE4Build.BuildWithUBT(String TargetName, UnrealTargetPlatform TargetPlatform, String Config, FileReference UprojectPath, Boolean ForceMonolithic, Boolean ForceNonUnity, Boolean ForceDebugInfo, Boolean ForceFlushMac, Boolean DisableXGE, String InAddArgs, Boolean ForceUnity, Dictionary`2 EnvVars)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.UE4Build.Build(BuildAgenda Agenda, Nullable`1 InDeleteBuildProducts, Boolean InUpdateVersionFiles, Boolean InForceNoXGE, Boolean InUseParallelExecutor, Boolean InForceNonUnity, Boolean InForceUnity, Boolean InShowProgress, Dictionary`2 PlatformEnvVars, Nullable`1 InChangelistNumberOverride, Dictio
nary`2 InTargetToManifest)
UATHelper: Packaging (Windows (64-bit)):    at Project.Build(BuildCommand Command, ProjectParams Params, Int32 WorkingCL, ProjectBuildTargets TargetMask)
UATHelper: Packaging (Windows (64-bit)):    at BuildCookRun.DoBuildCookRun(ProjectParams Params)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.BuildCommand.Execute()
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.Automation.Execute(List`1 CommandsToExecute, CaselessDictionary`1 Commands)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.Automation.Process(String[] Arguments)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.Program.MainProc(Object Param)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.InternalUtils.RunSingleInstance(Func`2 Main, Object Param)
UATHelper: Packaging (Windows (64-bit)):    at AutomationTool.Program.Main()
UATHelper: Packaging (Windows (64-bit)): Program.Main: AutomationTool exiting with ExitCode=5 (5)
UATHelper: Packaging (Windows (64-bit)): BUILD FAILED
PackagingResults:Error: Error Unknown Error

I kinda fixed it by changing the blueprint it kept trying to nativize.