Bukkit

@unclemark

He could try running it at a lower frequency (specified in the command), but it's still likely to occasionally pause due to low memory. When it does so, it will try to initiate garbage collection to free up memory, and will automatically continue the Fill once enough free memory (500 MB +) is available.

I'd also recommend with only 1 GB memory to temporarily remove any other mods from the server while running the Fill. Especially if you're running something like Dynmap.

@BSidiocy

Assuming you don't want people to be kept within the border, you can remove the border for the world in question with the clear command.

@Kipklysmic

First, a couple of things to note:
Remember that capitalization matters in the world name. Normally the first created world is "world" with no capitalization.
The default values for freq and pad are 5000 and 208 respectively, so there's no need to specify them at all in the command if you're fine with the defaults.

I just tested in Spigot 1.8.7-R0.1-SNAPSHOT to be sure, and a slightly modified version of what you posted worked fine for me from server console:
wb world trim 5000 208

The error you received is triggered when it tries to read what you specified in the command (if anything) for freq and pad as integers (whole numbers, no decimal place, no letters or anything else but numbers). If trying to read either of those values as an integer fails, it gives you that error.
There's no reason you should get that error unless you messed the command up.

@dutchrastacraft

Sorry, there isn't. If you just want to disable the border, there are a few ways to do that, just off the top of my head setting knockback to 0 will make it disable the border check.

You wouldn't want to set bypass for most of the server anyway, as that is stored in a list and having the plugin check through a long list of most or all people ever on the server for each border check would be very inefficient and prone to causing lag.

If you're just wanting a few people to be stuck inside the border, I can't think of an efficient way to do that with how the plugin is designed; it was never really intended to work that way.

@ServerElementals

There are no options to automatically create a border, sorry. You'd need to manually determine how far away from the desired border center the furthest building or whatever is and set the border based on that, or alternately find the furthest spots in two opposite directions and set the border based on those corner locations.

@ItIsMeMyself

For reference, WorldBorder uses "TeleportCause.PLUGIN".

@ItIsMeMyself

The only way that should be able to happen which would leave a player outside the border is if another plugin is preventing a player from being teleported (assuming the player hasn't been granted permission to be outside the border).

@Z3dd7

This has always been possible since Minecraft generates terrain out to a certain distance from any player, and is why the Fill command has a configurable padding value.

If players are now being able to get further beyond the border before being knocked back, that indicates that your server is overloaded and not keeping up. This could be due to more needy plugins, or more players than you've had before, or anything else that might lead to a more stressed server.

@doomlordking

Yes, the Fill command fully generates everything (snow, trees, dungeons, etc.).

@sebas0987

I'm not sure I understand the question; nobody is allowed beyond the border unless they've been specifically granted the ability to do so.