请问这个错误是啥原因
错误号: 0
事件: Run-time error
描述: [string "Plugin: pkuxkx_status"]:1175: attempt to perform arithmetic on a nil value
stack traceback:
[string "Plugin: pkuxkx_status"]:1175: in function <[string "Plugin: pkuxkx_status"]:1164>
(tail call): ?
[string "Plugin: pkuxkx_status"]:181: in function <[string "Plugin: pkuxkx_status"]:178>
(tail call): ?
[string "Plugin: pkuxkx_status"]:81: in function <[string "Plugin: pkuxkx_status"]:68>
调用者: Function/Sub: OnPluginTelnetSubnegotiation called by 插件 pkuxkx_status