I'm getting this as well using runClient and trying to launch the client from the Mojang launcher (forged) without any other mods added.
---- Minecraft Crash Report ----
// You're mean.
Time: 6/9/19 9:31 AM
Description: Rendering screen
java.lang.NullPointerException: Rendering screen
at net.minecraftforge.fml.ModList.size(ModList.java:164) ~[?:?] {pl:eventbus:A,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraftforge.fml.BrandingControl.computeBranding(BrandingControl.java:59) ~[?:?] {pl:eventbus:A,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraftforge.fml.BrandingControl.getBrandings(BrandingControl.java:68) ~[?:?] {pl:eventbus:A,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraftforge.fml.BrandingControl.forEachLine(BrandingControl.java:77) ~[?:?] {pl:eventbus:A,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraft.client.gui.screen.MainMenuScreen.render(MainMenuScreen.java:248) ~[?:?] {pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:358) ~[?:?] {pl:eventbus:A,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraft.client.renderer.GameRenderer.func_195458_a(GameRenderer.java:554) ~[?:?] {pl:accesstransformer:B,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:898) ~[?:?] {pl:accesstransformer:B,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:384) ~[?:?] {pl:accesstransformer:B,pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at net.minecraft.client.main.Main.main(SourceFile:154) ~[1.14.2-forge-26.0.12.jar:?] {pl:object_holder_definalize:A,pl:runtime_enum_extender:A,pl:capability_inject_definalize:A,pl:runtimedistcleaner:A}
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_74] {}
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_74] {}
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_74] {}
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_74] {}
at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:51) ~[forge-1.14.2-26.0.12.jar:26.0] {}
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:19) [modlauncher-2.1.1.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:32) [modlauncher-2.1.1.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:50) [modlauncher-2.1.1.jar:?] {}
at cpw.mods.modlauncher.Launcher.run(Launcher.java:59) [modlauncher-2.1.1.jar:?] {}
at cpw.mods.modlauncher.Launcher.main(Launcher.java:44) [modlauncher-2.1.1.jar:?] {}
A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------
-- Head --
Thread: Client thread
Stacktrace:
at net.minecraftforge.fml.ModList.size(ModList.java:164)
at net.minecraftforge.fml.BrandingControl.computeBranding(BrandingControl.java:59)
at net.minecraftforge.fml.BrandingControl.getBrandings(BrandingControl.java:68)
at net.minecraftforge.fml.BrandingControl.forEachLine(BrandingControl.java:77)
at net.minecraft.client.gui.screen.MainMenuScreen.render(MainMenuScreen.java:248)
at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:358)
-- Screen render details --
Details:
Screen name: net.minecraft.client.gui.screen.MainMenuScreen
Mouse location: Scaled: (0, 0). Absolute: (0.000000, 0.000000)
Screen size: Scaled: (570, 320). Absolute: (1708, 960). Scale factor of 3.000000
Stacktrace:
at net.minecraft.client.renderer.GameRenderer.func_195458_a(GameRenderer.java:554)
at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:898)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:384)
at net.minecraft.client.main.Main.main(SourceFile:154)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:51)
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:19)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:32)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:50)
at cpw.mods.modlauncher.Launcher.run(Launcher.java:59)
at cpw.mods.modlauncher.Launcher.main(Launcher.java:44)
-- System Details --
Details:
Minecraft Version: 1.14.2
Operating System: Mac OS X (x86_64) version 10.14.5
Java Version: 1.8.0_74, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1364859008 bytes (1301 MB) / 2147483648 bytes (2048 MB) up to 2147483648 bytes (2048 MB)
JVM Flags: 8 total; -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
FML: New FML!
Loaded coremods (and transformers): Nothing
Launched Version: 1.14.2-forge-26.0.12
LWJGL: 3.2.1 build 12
OpenGL: AMD Radeon Pro 560 OpenGL Engine GL version 2.1 ATI-2.9.26, ATI Technologies Inc.
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because ARB_framebuffer_object is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.
Using VBOs: Yes
Is Modded: Definitely; Client brand changed to 'forge'
Type: Client (map_client.txt)
Resource Packs: mod:xaerominimap, mod:forge, vanilla
Current Language: English (US)
CPU: 8x Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz