Could I get some help here, as I'm not sure what to do.
[18:16:33] [Server thread/WARN] [Sponge]: World [ultraspace] (24) is attempting to be registered as an existing dimension but it's dimension id has already been registered for folder [null]. This means the world has been copied outside of Sponge. This is not a supported configuration.
[18:16:33] [Server thread/INFO] [FML.ModTracker]: This world was saved with mod aearlymodloader version 8.3.0 and it is now at version 8.4.2, things may not work well
[18:16:33] [Server thread/INFO] [FML.ModTracker]: This world was saved with mod pixelmon version 8.3.0 and it is now at version 8.4.2, things may not work well
[18:16:33] [Server thread/INFO] [FML]: Injecting existing registry data into this server instance
[18:16:34] [Server thread/INFO] [FML]: Registry SoundEvent: Found a missing id from the world pixelmon:pixelmon.mob.umbreonf
[18:16:34] [Server thread/INFO] [FML]: Registry SoundEvent: Found a missing id from the world pixelmon:pixelmon.mob.umbreonm
[18:16:34] [Server thread/INFO] [FML]: Registry SoundEvent: Found a missing id from the world pixelmon:pixelmon.mob.trapinchf
[18:16:34] [Server thread/INFO] [FML]: Registry SoundEvent: Found a missing id from the world pixelmon:pixelmon.mob.trapinchm
[18:16:34] [Server thread/ERROR] [FML]: Unidentified mapping from registry minecraft:soundevents
[18:16:34] [Server thread/ERROR] [FML]: pixelmon:pixelmon.mob.trapinchf: 908
[18:16:34] [Server thread/ERROR] [FML]: pixelmon:pixelmon.mob.trapinchm: 909
[18:16:34] [Server thread/ERROR] [FML]: pixelmon:pixelmon.mob.umbreonm: 789
[18:16:34] [Server thread/ERROR] [FML]: pixelmon:pixelmon.mob.umbreonf: 788
[18:16:34] [Server thread/WARN] [FML]: Forge Mod Loader detected missing registry entries.
There are 4 missing entries in this save.
If you continue the missing entries will get removed.
A world backup will be automatically created in your saves directory.
Missing minecraft:soundevents:
pixelmon:pixelmon.mob.trapinchf
pixelmon:pixelmon.mob.umbreonm
pixelmon:pixelmon.mob.umbreonf
pixelmon:pixelmon.mob.trapinchm
Run the command /fml confirm or or /fml cancel to proceed.
Alternatively start the server with -Dfml.queryResult=confirm or -Dfml.queryResult=cancel to preselect the answer.