Pye

all I put into the generator settings is the stuff you type in to make the tunnelers dream preset

so I can't use any flat world except the default one then

thats what it said in the log

[22:14:00] [main/FATAL]: Failed to start the minecraft server com.google.gson.JsonParseException: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $ at net.minecraft.server.v1_16_R3.ChatDeserializer.a(SourceFile:495) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.ChatDeserializer.a(SourceFile:545) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.ChatDeserializer.a(SourceFile:541) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.ChatDeserializer.a(SourceFile:549) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.GeneratorSettings.a(GeneratorSettings.java:236) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.DedicatedServerProperties.<init>(DedicatedServerProperties.java:127) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.DedicatedServerProperties.load(DedicatedServerProperties.java:132) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.DedicatedServerSettings.<init>(DedicatedServerSettings.java:20) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.Main.main(Main.java:105) ~[patched_1.16.5.jar:git-Paper-771] at org.bukkit.craftbukkit.Main.main(Main.java:289) ~[patched_1.16.5.jar:git-Paper-771] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?] at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?] at io.papermc.paperclip.Paperclip.main(Paperclip.java:58) ~[server.jar:?] Caused by: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $ at com.google.gson.stream.JsonReader.syntaxError(JsonReader.java:1559) ~[patched_1.16.5.jar:git-Paper-771] at com.google.gson.stream.JsonReader.checkLenient(JsonReader.java:1401) ~[patched_1.16.5.jar:git-Paper-771] at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:593) ~[patched_1.16.5.jar:git-Paper-771] at com.google.gson.stream.JsonReader.peek(JsonReader.java:425) ~[patched_1.16.5.jar:git-Paper-771] at com.google.gson.internal.bind.TypeAdapters$29.read(TypeAdapters.java:716) ~[patched_1.16.5.jar:git-Paper-771] at com.google.gson.internal.bind.TypeAdapters$29.read(TypeAdapters.java:714) ~[patched_1.16.5.jar:git-Paper-771] at com.google.gson.internal.bind.TypeAdapters$35$1.read(TypeAdapters.java:910) ~[patched_1.16.5.jar:git-Paper-771] at net.minecraft.server.v1_16_R3.ChatDeserializer.a(SourceFile:493) ~[patched_1.16.5.jar:git-Paper-771] ... 14 more

I repaired the core files in danger zone and it still didn't work

When I press start it either doesn't do anything, or it says starting and then goes back to saying offline