openwrt-18.06 源码 显示出错，也不显示用户选择菜单。

[xftv5608]

Failed to execute arcombine dispatcher target for entry '/admin/network/appfilter'.
The called action terminated with an exception:
/usr/lib/lua/luci/util.lua:222: attempt to get length of local 'str' (a boolean value)
stack traceback:
/usr/lib/lua/luci/util.lua:222: in function 'split'
/usr/lib/lua/luci/model/cbi/appfilter/appfilter.lua:186: in function 'func'
/usr/lib/lua/luci/cbi.lua:66: in function 'load'
/usr/lib/lua/luci/dispatcher.lua:845: in function 'target'
/usr/lib/lua/luci/dispatcher.lua:963: in function </usr/lib/lua/luci/dispatcher.lua:959>