"riddled with difficulties" is a grammatically correct and commonly used phrase in written English.
It can be used to describe a situation or problem that is full of challenges or complications. Example: The project was riddled with difficulties from the start, but we persevered and were able to complete it successfully.
The enterprise has been riddled with difficulties.
Inevitably, perhaps, the census has been riddled with difficulties.
CCS has never been demonstrated at scale and the test projects underway are riddled with difficulties.
Trump's track record with the American Jewish community has been riddled with difficulties from the start of his presidency.
Although there are ongoing efforts to establish expert hierarchies in various domains, these attempts are riddled with difficulties.
That is because, for complicated theoretical reasons that have to do with the nature of the strong nuclear force, calculating the precise probabilities for different types of D-meson decays is riddled with difficulty.
The first shows were riddled with difficulty, starting with the collapse of the big top after the increased weight of rainwater caused the central mast to snap.
The domestic game is riddled with economic difficulties compounded by a reputation for match-fixing which has disillusioned fans.
The Revel casino a $2.4 billion monstrosity that opened in 2012, only to fold two years later, riddled with financial difficulties, which Paumgarten documented was the highest-profile zany scheme to hold out the promise of growth and riches in recent years, but became a towering symbol of spectacular, Atlantic City-style failure.
The problem of accounting for epistemic uncertainty in risk management decisions is conceptually straightforward, but is riddled with practical difficulties.
Trouble is, though, that while they might look great in the obligatory power-point presentations, these plans are riddled with profound operational difficulties – many of which bring with them, once people understand what's at stake, the potential for huge public rows.
