2 Plugins are not working properly

Hello,

two plugins in my server (Staff+ and CommandPanels) arent working properly and the console is getting spammed by errors.

I had the latest versions and I changed them but nothing changed.

Here is the log: https://mclo.gs/D8mhjVh

Edit: i am playing in 1.8.9 by using ViaRewind plugin as the server is 1.12

arlight thx