Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: A former 5-star product that's now a zero-star product

We bought this years ago, and it has worked perfectly in two microwaves. But this morning I heated some water as usual, but in a different microwave. Within a minute, I had the same thing that others have reported: flame, smoke, soot, and melted plastic odor. There's a definitely a hole in the lid now where it melted through.The microwave seems to be working OK now, but we'll have to figure out how to clean out the black stains inside the microwave.