crashing on start (multicraft)

I am launching the server with forge 1.12.2 latest and have followed many tutorials on how to install it and it seems to be working fine for them but not me.

I would very grateful if someone were to help me, thanks!

Here is what is displays in console on server startup!

10.01 01:29:46 [Multicraft] Starting server!
10.01 01:29:46 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:29:46 [Multicraft] Updating eula.txt file
10.01 01:29:46 [Server] INFO A problem occurred running the Server launcher.java.lang.reflect.InvocationTargetException
10.01 01:29:46 [Server] INFO at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
10.01 01:29:46 [Server] INFO at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
10.01 01:29:46 [Server] INFO at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
10.01 01:29:46 [Server] INFO at java.base/java.lang.reflect.Method.invoke(Method.java:566)
10.01 01:29:46 [Server] INFO at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:70)
10.01 01:29:46 [Server] INFO at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:34)
10.01 01:29:46 [Server] INFO Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
10.01 01:29:46 [Server] INFO at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
10.01 01:29:46 [Server] INFO at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
10.01 01:29:46 [Server] INFO ... 6 more
10.01 01:29:46 [Multicraft] Server shut down (starting)
10.01 01:29:46 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:29:46 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:29:46 [Multicraft] Server stopped
10.01 01:29:51 [Multicraft] Loading server properties
10.01 01:29:51 [Multicraft] Starting server!
10.01 01:29:51 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:29:51 [Multicraft] Updating eula.txt file
10.01 01:29:51 [Server] INFO A problem occurred running the Server launcher.java.lang.reflect.InvocationTargetException
10.01 01:29:51 [Server] INFO at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
10.01 01:29:51 [Server] INFO at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
10.01 01:29:51 [Server] INFO at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
10.01 01:29:51 [Server] INFO at java.base/java.lang.reflect.Method.invoke(Method.java:566)
10.01 01:29:51 [Server] INFO at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:70)
10.01 01:29:51 [Server] INFO at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:34)
10.01 01:29:51 [Server] INFO Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
10.01 01:29:51 [Server] INFO at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
10.01 01:29:51 [Server] INFO at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
10.01 01:29:51 [Server] INFO ... 6 more
10.01 01:29:51 [Multicraft] Server shut down (starting)
10.01 01:29:51 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:29:51 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:29:51 [Multicraft] Server stopped
10.01 01:29:52 [Multicraft] Received stop command
10.01 01:29:52 [Multicraft] Server stopped
10.01 01:38:19 [Multicraft] Received start command
10.01 01:38:19 [Multicraft] Loading server properties
10.01 01:38:19 [Multicraft] Starting server!
10.01 01:38:19 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:38:19 [Multicraft] JAR file not found, copying from global JAR directory
10.01 01:38:19 [Multicraft] Failed to copy jarfile from global JAR directory
10.01 01:38:19 [Multicraft] JAR file not found. Go to "Settings"-"Update Minecraft" to download the JAR file.
10.01 01:38:19 [Multicraft] Updating eula.txt file
10.01 01:38:19 [Server] INFO Error: Unable to access jarfile /custom.jar
10.01 01:38:19 [Multicraft] Server shut down (starting)
10.01 01:38:19 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:38:19 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:38:19 [Multicraft] Server stopped
10.01 01:38:24 [Multicraft] Loading server properties
10.01 01:38:24 [Multicraft] Starting server!
10.01 01:38:24 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:38:24 [Multicraft] JAR file not found, copying from global JAR directory
10.01 01:38:24 [Multicraft] Failed to copy jarfile from global JAR directory
10.01 01:38:24 [Multicraft] JAR file not found. Go to "Settings"-"Update Minecraft" to download the JAR file.
10.01 01:38:24 [Multicraft] Updating eula.txt file
10.01 01:38:24 [Server] INFO Error: Unable to access jarfile /custom.jar
10.01 01:38:24 [Multicraft] Server shut down (starting)
10.01 01:38:24 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:38:24 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:38:24 [Multicraft] Server stopped
10.01 01:38:29 [Multicraft] Loading server properties
10.01 01:38:29 [Multicraft] Starting server!
10.01 01:38:29 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:38:29 [Multicraft] JAR file not found, copying from global JAR directory
10.01 01:38:30 [Multicraft] Failed to copy jarfile from global JAR directory
10.01 01:38:30 [Multicraft] JAR file not found. Go to "Settings"-"Update Minecraft" to download the JAR file.
10.01 01:38:30 [Multicraft] Updating eula.txt file
10.01 01:38:30 [Server] INFO Error: Unable to access jarfile /custom.jar
10.01 01:38:30 [Multicraft] Server shut down (starting)
10.01 01:38:30 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:38:30 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:38:30 [Multicraft] Server stopped
10.01 01:38:34 [Multicraft] Received stop command
10.01 01:38:34 [Multicraft] Server stopped
10.01 01:38:59 [Multicraft] Received start command
10.01 01:38:59 [Multicraft] Loading server properties
10.01 01:38:59 [Multicraft] Starting server!
10.01 01:38:59 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:38:59 [Multicraft] JAR file not found, copying from global JAR directory
10.01 01:38:59 [Multicraft] Failed to copy jarfile from global JAR directory
10.01 01:38:59 [Multicraft] JAR file not found. Go to "Settings"-"Update Minecraft" to download the JAR file.
10.01 01:38:59 [Multicraft] Updating eula.txt file
10.01 01:38:59 [Server] INFO Error: Unable to access jarfile /custom.jar
10.01 01:38:59 [Multicraft] Server shut down (starting)
10.01 01:38:59 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:38:59 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:38:59 [Multicraft] Server stopped
10.01 01:39:04 [Multicraft] Loading server properties
10.01 01:39:04 [Multicraft] Starting server!
10.01 01:39:04 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:39:04 [Multicraft] JAR file not found, copying from global JAR directory
10.01 01:39:04 [Multicraft] Failed to copy jarfile from global JAR directory
10.01 01:39:04 [Multicraft] JAR file not found. Go to "Settings"-"Update Minecraft" to download the JAR file.
10.01 01:39:04 [Multicraft] Updating eula.txt file
10.01 01:39:04 [Server] INFO Error: Unable to access jarfile /custom.jar
10.01 01:39:04 [Multicraft] Server shut down (starting)
10.01 01:39:04 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:39:04 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:39:04 [Multicraft] Server stopped
10.01 01:39:09 [Multicraft] Loading server properties
10.01 01:39:09 [Multicraft] Starting server!
10.01 01:39:09 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:39:09 [Multicraft] JAR file not found, copying from global JAR directory
10.01 01:39:09 [Multicraft] Failed to copy jarfile from global JAR directory
10.01 01:39:09 [Multicraft] JAR file not found. Go to "Settings"-"Update Minecraft" to download the JAR file.
10.01 01:39:09 [Multicraft] Updating eula.txt file
10.01 01:39:09 [Server] INFO Error: Unable to access jarfile /custom.jar
10.01 01:39:09 [Multicraft] Server shut down (starting)
10.01 01:39:09 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:39:09 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:39:09 [Multicraft] Server stopped
10.01 01:39:14 [Multicraft] Loading server properties
10.01 01:39:14 [Multicraft] Starting server!
10.01 01:39:14 [Multicraft] Loaded config for "Custom.jar (Use and upload your own JAR)"
10.01 01:39:14 [Multicraft] JAR file not found, copying from global JAR directory
10.01 01:39:14 [Multicraft] Failed to copy jarfile from global JAR directory
10.01 01:39:14 [Multicraft] JAR file not found. Go to "Settings"-"Update Minecraft" to download the JAR file.
10.01 01:39:14 [Multicraft] Updating eula.txt file
10.01 01:39:14 [Server] INFO Error: Unable to access jarfile /custom.jar
10.01 01:39:14 [Multicraft] Server shut down (starting)
10.01 01:39:14 [Multicraft] Restarting crashed server in 5 seconds
10.01 01:39:14 [Multicraft] Looks like a crash, check the server console. Return value: 1
10.01 01:39:14 [Multicraft] Server stopped
10.01 01:39:18 [Multicraft] Received stop command
10.01 01:39:18 [Multicraft] Server stopped