Three of the prosecution's witnesses proved troublesome for its case.

It was an old one, but of a make which could prove troublesome.

Publishing the series proved troublesome on account of its subject matter.

This is an area that has proved troublesome over the course of negotiations.

The big shot had decided that some turn of the reporter's conversation might prove troublesome.

Sometimes the death did not happen, and that could prove troublesome unless you had a quick excuse ready.

"But will not the trees and hills there prove troublesome?"

Finding someone to handle the effort in the rest of the world proved more troublesome.

It's only while you're still here that they may prove troublesome.

The computer software for the aircraft has also proved troublesome, it said.