Plugins

Hey! So i wanted to ask for ur help! I have problems with theese 2 plugins.
1. When i install factions ( with everything needed massivecore,vault) it shows me that factions is working but when i try any of the command it doesnt work. I want to know the problem so plz help me.
2. I installed Citizens and the plugin is red. I tried everything but nothing worked. Mby the plugin doesnt work if i have different plugins that may block it. If it is like that then plz tell me, and plz tell me how to make them work.
Btw my server is running 1.12.

so how can i make them work ? i have to change version of the server?