I've installed the latest version of WorldBorder for 1.13.1 and I'm using PaperSpigot build 262 (1.13.1) with Dynmap-3.0-SNAPSHOT-spigot.jar (1.13.1). I issued a wb bypass smmmadden from the console and it worked perfectly and updated the config file automatically. I then went into the game and issued the same command for my wife's admin account and the config was updated, but server crashed immediately afterward.

See crash report here
crash-2018-09-16_23.04.02-server.txt

Where it crashed:

Not clear if this is WB, Dynmap or Paper related.
-Steve

Wouldn't expect it to be anything to do with WorldBorder, and the stack trace contains only NMS code references. Looks to be a problem with Paper/Spigot/Bukkit/Minecraft rather than a plugin, based on that.