Roof AC leaking around the gasket

Roof AC leaks are almost always the gasket between the AC base and the roof, not the unit itself. Over a few seasons UV and roof movement compress and crack that foam gasket. Pull the shroud, inspect the gasket for compression set or cracking, and re-bed if it's not seated evenly — a lot of leaks come from an AC that was never torqued down evenly on all bolts. If the gasket looks fine, check the roof membrane itself around the opening for separation. Is this a new leak or has it been slow for a while?