Definition: a complicated problem, a tangled mess of problems
If we layoff a few employees, it opens a can of worms. You fire a few people, then the media says your company is sick, then investors start to worry, and your customers call your competitors, etc. The problems don’t stop coming.
If I am late to work today, it will open a big can of worms. My boss already doesn’t like me. He thinks I am lazy, and that I always miss my objectives. If I am late today, it will just make it worse.