Game crashes every time the button tied to the tool type is pressed.

For any bug reports please provide the following details as well,

• MC Version: 16.5
• C&B Version:1.0.43
• Do You have Optifine: Happens with and without Optifine

crash report: java.lang.NullPointerException: Unexpected error
at mod.chiselsandbits.client.screens.widgets.ToolModeSelectionWidget.init(ToolModeSelectionWidget.java:151) ~[?:1.0.43] {re:classloading}
at mod.chiselsandbits.api.client.screen.AbstractChiselsAndBitsScreen.func_230481_d_(AbstractChiselsAndBitsScreen.java:51) ~[?:1.0.43] {re:classloading}
at net.minecraft.client.gui.screen.Screen.func_230480_a_(Screen.java:107) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:computing_frames,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:quark.mixins.json:client.ScreenMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at mod.chiselsandbits.api.client.screen.AbstractChiselsAndBitsScreen.func_230480_a_(AbstractChiselsAndBitsScreen.java:43) ~[?:1.0.43] {re:classloading}
at mod.chiselsandbits.client.screens.ToolModeSelectionScreen.func_231160_c_(ToolModeSelectionScreen.java:47) ~[?:1.0.43] {re:classloading}
at net.minecraft.client.gui.screen.Screen.func_231158_b_(Screen.java:325) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:computing_frames,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:quark.mixins.json:client.ScreenMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at net.minecraft.client.Minecraft.func_147108_a(Minecraft.java:852) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:mining_helmet.mixins.json:MinecraftMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at mod.chiselsandbits.keys.KeyBindingManager.handleKeyPresses(KeyBindingManager.java:122) ~[?:1.0.43] {re:classloading}
at mod.chiselsandbits.keys.KeyBindingManager.handleClientTickEvent(KeyBindingManager.java:103) ~[?:1.0.43] {re:classloading}
at net.minecraftforge.eventbus.ASMEventHandler_656_KeyBindingManager_handleClientTickEvent_ClientTickEvent.invoke(.dynamic) ~[?:?] {}
at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85) ~[eventbus-4.0.0.jar:?] {}
at net.minecraftforge.eventbus.EventBus$$Lambda$2595/714402061.invoke(Unknown Source) ~[?:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-4.0.0.jar:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-4.0.0.jar:?] {}
at net.minecraftforge.fml.hooks.BasicEventHooks.onPreClientTick(BasicEventHooks.java:105) ~[?:?] {re:classloading}
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1414) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:mining_helmet.mixins.json:MinecraftMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:953) [?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:mining_helmet.mixins.json:MinecraftMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:607) [?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:mining_helmet.mixins.json:MinecraftMixin,pl:mixin:A,pl:runtimedistcleaner:A}
at net.minecraft.client.main.Main.main(Main.java:184) [?:?] {re:classloading,pl:runtimedistcleaner:A}
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_51] {}
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_51] {}
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_51] {}
at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_51] {}
at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:51) [forge-1.16.5-36.2.0.jar:36.2] {}
at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$457/230266757.call(Unknown Source) [forge-1.16.5-36.2.0.jar:36.2] {}
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-8.0.9.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-8.0.9.jar:?] {}
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-8.0.9.jar:?] {}
at cpw.mods.modlauncher.Launcher.run(Launcher.java:82) [modlauncher-8.0.9.jar:?] {re:classloading}
at cpw.mods.modlauncher.Launcher.main(Launcher.java:66) [modlauncher-8.0.9.jar:?] {re:classloading}

I've also experienced this (stack trace here)

Having identical issues as well, unsure about how many of the tools supporting that GUI do this, so far it only seems to be the pattern that is the culprit (for me at least)

Fixed in the 1.18 update.