Error from the console:
org.json.JSONException: JSONObject["data"] is not a JSONObject (class org.json.JSONObject$Null : null).
at org.json.JSONObject.wrongValueFormatException(JSONObject.java:2698)
at org.json.JSONObject.getJSONObject(JSONObject.java:784)
at de.hellbz.forge.Utils.Data.getValueFromJSONObject(Data.java:283)
at de.hellbz.forge.Utils.Data.getJsonValue(Data.java:267)
at de.hellbz.forge.Utils.Remote.requestUniqueID(Remote.java:97)
at de.hellbz.forge.Utils.Remote.checkForUpdate(Remote.java:29)
at de.hellbz.forge.ServerStarter.main(ServerStarter.java:85)
Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.equals(Object)" because "newUniqueId" is null
at de.hellbz.forge.Utils.Remote.requestUniqueID(Remote.java:99)
at de.hellbz.forge.Utils.Remote.checkForUpdate(Remote.java:29)
at de.hellbz.forge.ServerStarter.main(ServerStarter.java:85)

Thanks for Reporting.

Please give this a Try.

https://s.hellbz.de/f/minecraft_server_v3.5.7.jar

Next time, please open just there a Issuse,
i removed the other from CurseForge right now.

There was also an error in my unique ID script,
which is why no new servers have been registered since the release,
thanks for that too.