job manager

Hi
I had a job manager plugin and I add some css to customise it nd it is work grate
but I add a wordpress network because I want to add a new site

now when I try to access job page there is nothing (empty page with no error)

and when I try to view the jobs from job list (backend ) it give me an 404 error

should I activate a job manager plugin from network admin ? if so are we going to lose this css that I add it ?

or what should I do ,
please advice me ASAP

thank you

[No bumping, thank you.]