OpenWrt安装luci-app-statistics之后，点击任何一个TAB后出现类似如下提示：
/usr/lib/lua/luci/dispatcher.lua:474: Failed to execute call dispatcher target for entry '/admin/statistics/graph/cpu'. The called action terminated with an exception: /usr/lib/lua/luci/util.lua:200: attempt to get length of local 'str' (a nil value) stack traceback: [C]: in function 'assert' /usr/lib/lua/luci/dispatcher.lua:474: in function 'dispatch' /usr/lib/lua/luci/dispatcher.lua:126: in function </usr/lib/lua/luci/dispatcher.lua:125>
打开/etc/init.d/luci_statistics文件
在chmod 1777 /tmp下一行添加
chmod 0755 /etc/config/luci_statistics
解决。如果不能解决，手动将/etc/config/luci_statistics文件改为0755，或者重启路由器。