Polished Floor Disaster. Rough with bubbles what is this?

We wanted to re-polish our floorboards so we lightly sanded the floors and put a coat of floor polish with a roller and they turned up beautiful. But the second coat, after we lightly sanded again and put the second coat of floor polish, it has a lot of rough spots and what appears to be bubbles underneath. The stairs and rails are also rough to touch. Tried to sand the floors again (with a 1/3 sheet hand held sander) and it just keeps peeling. It was 19 hours between coats. Please tell me what has happened to my beautiful floors. Thanks