I have an someone at work who is currently in the process of applying for a greencard renewal (f48 I think). They sent out their application nearly a year ago n

I have an someone at work who is currently in the process of applying for a greencard renewal (f48 I think). They sent out their application nearly a year ago now and are still waiting for the result. Is this cause for concern? Should they hire an immigration lawyer? Is there a chance for them to be denied even though they've been here over a decade as a productive, law-abiding member of society?