here is the crash report

Description: Rendering Block Entity

java.lang.NullPointerException: Cannot invoke "net.minecraft.class_4730.method_24145(net.minecraft.class_4597, java.util.function.Function)" because "material" is null
at knot//net.mehvahdjukaar.amendments.client.renderers.HangingSignRendererExtension.render(HangingSignRendererExtension.java:109)
at knot//net.minecraft.class_7761.handler$zfg000$amendments$renderEnhancedSign(class_7761.java:563)
at knot//net.minecraft.class_7761.method_23083(class_7761.java)
at knot//net.minecraft.class_7761.method_3569(class_7761.java:30)
at knot//net.minecraft.class_824.method_23079(class_824.java:90)
at knot//net.minecraft.class_824.method_23081(class_824.java:79)
at knot//net.minecraft.class_824.method_3554(class_824.java:104)
at knot//net.minecraft.class_824.method_3555(class_824.java:79)
at knot//net.minecraft.class_761.redirect$ghj000$valkyrienskies$renderShipChunkBlockEntity(class_761.java:11991)
at knot//net.minecraft.class_761.method_22710(class_761.java:1367)
at knot//net.minecraft.class_757.method_3188(class_757.java:1110)
at knot//net.minecraft.class_757.method_3192(class_757.java:880)
at knot//net.minecraft.class_310.method_1523(class_310.java:1219)
at knot//net.minecraft.class_310.method_1514(class_310.java:802)
at knot//net.minecraft.client.main.Main.main(Main.java:250)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:480)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:243)
at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:278)
at org.multimc.EntryPoint.listen(EntryPoint.java:143)
at org.multimc.EntryPoint.main(EntryPoint.java:34)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Render thread
Stacktrace:
at knot//net.mehvahdjukaar.amendments.client.renderers.HangingSignRendererExtension.render(HangingSignRendererExtension.java:109)
at knot//net.minecraft.class_7761.handler$zfg000$amendments$renderEnhancedSign(class_7761.java:563)
at knot//net.minecraft.class_7761.method_23083(class_7761.java)
at knot//net.minecraft.class_7761.method_3569(class_7761.java:30)
at knot//net.minecraft.class_824.method_23079(class_824.java:90)
at knot//net.minecraft.class_824.method_23081(class_824.java:79)
at knot//net.minecraft.class_824.method_3554(class_824.java:104)
at knot//net.minecraft.class_824.method_3555(class_824.java:79)
at knot//net.minecraft.class_761.redirect$ghj000$valkyrienskies$renderShipChunkBlockEntity(class_761.java:11991)
at knot//net.minecraft.class_761.method_22710(class_761.java:1367)
at knot//net.minecraft.class_757.method_3188(class_757.java:1110)

-- Block Entity Details --
Details:
Name: minecraft:hanging_sign // net.minecraft.class_7717
Block: Block{would:willow_wall_hanging_sign}[facing=north,waterlogged=false]
Block location: World: (-16,84,87), Section: (at 0,4,7 in -1,5,5; chunk contains blocks -16,-64,80 to -1,319,95), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,-64,0 to -1,319,511)
Block: Block{would:willow_wall_hanging_sign}[facing=north,waterlogged=false]
Block location: World: (-16,84,87), Section: (at 0,4,7 in -1,5,5; chunk contains blocks -16,-64,80 to -1,319,95), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,-64,0 to -1,319,511)
Stacktrace:
at knot//net.minecraft.class_824.method_3554(class_824.java:104)
at knot//net.minecraft.class_824.method_3555(class_824.java:79)
at knot//net.minecraft.class_761.redirect$ghj000$valkyrienskies$renderShipChunkBlockEntity(class_761.java:11991)
at knot//net.minecraft.class_761.method_22710(class_761.java:1367)
at knot//net.minecraft.class_757.method_3188(class_757.java:1110)
at knot//net.minecraft.class_757.method_3192(class_757.java:880)
at knot//net.minecraft.class_310.method_1523(class_310.java:1219)
at knot//net.minecraft.class_310.method_1514(class_310.java:802)
at knot//net.minecraft.client.main.Main.main(Main.java:250)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:480)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:243)
at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:278)
at org.multimc.EntryPoint.listen(EntryPoint.java:143)
at org.multimc.EntryPoint.main(EntryPoint.java:34)