[1.15.2] Bug starting server

[detonatorss]

[27abr2020 15:15:05.957] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher running: args [--gameDir, ., --launchTarget, fmlserver, --fml.forgeVersion, 31.1.59, --fml.mcpVersion, 20200414.225201, --fml.mcVersion, 1.15.2, --fml.forgeGroup, net.minecraftforge]
[27abr2020 15:15:05.960] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher 5.1.0+69+master.79f13f7 starting: java version 1.8.0_241 by Oracle Corporation
[27abr2020 15:15:06.289] [main/INFO] [net.minecraftforge.fml.loading.FixSSL/CORE]: Added Lets Encrypt root certificates as additional trust
[27abr2020 15:15:06.950] [main/INFO] [cpw.mods.modlauncher.LaunchServiceHandler/MODLAUNCHER]: Launching target 'fmlserver' with arguments [--gameDir, .]
[27abr2020 15:15:13.458] [main/WARN] [net.minecraft.command.Commands/]: Ambiguity between arguments [teleport, destination] and [teleport, targets] with inputs: [Player, 0123, @e, dd12be42-52a9-4a91-a8a1-11c01849e498]
[27abr2020 15:15:13.460] [main/WARN] [net.minecraft.command.Commands/]: Ambiguity between arguments [teleport, location] and [teleport, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[27abr2020 15:15:13.484] [main/WARN] [net.minecraft.command.Commands/]: Ambiguity between arguments [teleport, location] and [teleport, targets] with inputs: [0.1 -0.5 .9, 0 0 0]
[27abr2020 15:15:13.486] [main/WARN] [net.minecraft.command.Commands/]: Ambiguity between arguments [teleport, targets] and [teleport, destination] with inputs: [Player, 0123, dd12be42-52a9-4a91-a8a1-11c01849e498]
[27abr2020 15:15:13.488] [main/WARN] [net.minecraft.command.Commands/]: Ambiguity between arguments [teleport, targets, location] and [teleport, targets, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[27abr2020 15:15:14.237] [Server thread/INFO] [net.minecraft.server.dedicated.DedicatedServer/]: Starting minecraft server version 1.15.2
[27abr2020 15:15:14.636] [Server thread/ERROR] [net.minecraft.server.MinecraftServer/]: Encountered an unexpected exception
java.lang.NullPointerException: null
    at net.minecraftforge.fml.loading.moddiscovery.BackgroundScanHandler.waitForScanToComplete(BackgroundScanHandler.java:97) ~[forge-1.15.2-31.1.59.jar:?]
    at net.minecraftforge.fml.ModLoader.gatherAndInitializeMods(ModLoader.java:178) ~[?:?]
    at net.minecraftforge.fml.server.ServerModLoader.begin(ServerModLoader.java:45) ~[?:?]
    at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:122) ~[?:?]
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:613) [?:?]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_241]
[27abr2020 15:15:14.645] [Server thread/ERROR] [net.minecraft.server.MinecraftServer/]: This crash report has been saved to: G:\Bibliotecas\Servers\1.15.2\.\crash-reports\crash-2020-04-27_15.15.14-server.txt
[27abr2020 15:15:14.684] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: Stopping server
[27abr2020 15:15:14.684] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: Saving worlds
[27abr2020 15:15:14.688] [Server thread/ERROR] [net.minecraft.server.MinecraftServer/]: Exception stopping the server
java.lang.IllegalArgumentException: Can not hotload overworld. This must be loaded at all times by main Server.
    at org.apache.commons.lang3.Validate.isTrue(Validate.java:158) ~[server-1.15.2-extra.jar:?]
    at net.minecraftforge.common.DimensionManager.initWorld(DimensionManager.java:229) ~[?:?]
    at net.minecraftforge.common.DimensionManager.getWorld(DimensionManager.java:198) ~[?:?]
    at net.minecraft.server.MinecraftServer.func_71218_a(MinecraftServer.java:1004) ~[?:?]
    at net.minecraft.server.MinecraftServer.func_213211_a(MinecraftServer.java:536) ~[?:?]
    at net.minecraft.server.MinecraftServer.func_71260_j(MinecraftServer.java:568) ~[?:?]
    at net.minecraft.server.dedicated.DedicatedServer.func_71260_j(DedicatedServer.java:550) ~[?:?]
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:676) [?:?]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_241]

It's all vanilla, recently started

Edited April 27, 2020 by detonatorss
my fault, i didn't realised that i need to specify if i was using mods or not

[detonatorss]

Thanks i will compile it by myself 

[detonatorss]

Just now, diesieben07 said:

Wat? No. Downgrade forge.

okay np, then i will downgrade hahaha