[throw] a (monkey|) wrench (into|in) the works

to slow down a plan or activity or prevent it from going on

The idiom "rain on someone's parade" originates from the notion of a sudden downpour spoiling an outdoor celebration or event. It is used figuratively to describe the act of spoiling someone's happiness, excitement, or plans by delivering unwelcome news, criticism, or negativity.

I hate it when someone throws a monkey wrench in the works.
The funding for the project was withdrawn so that really threw a wrench into the works.
The sudden change in regulations right before the product launch threw a wrench into the works for the marketing team.
The unexpected resignation of the project manager really threw a wrench into the works of our carefully planned timeline.
The economic downturn threw a wrench into the works of the company's expansion plans.