The phrase "difficulty in realising" is correct and usable in written English.
It can be used when discussing challenges or obstacles in understanding or achieving something.
Example: "She expressed her difficulty in realising the full potential of the project due to limited resources."
Alternatives: "struggle to understand" or "challenge in grasping".
Despite the recent progress, many Nepali transgender people still experience difficulties in realising their legal status.
Given the well known difficulties in realising 4% savings a year, leaping to 6-76-7% heroic.
The production staff encountered difficulties in realising a scene at the start of the film depicting an international teleconference being conducted using high-resolution viewing monitors.
Efforts that go 'against the grain' of wider professional, organisational and policy aims are likely to face significant difficulties in realising their ambitions, while interventions seeking to change behaviour without some form of professional endorsement are often on a hiding to nothing.
For all his display of confidence, two things stand out at the end of this week: the great difficulty he will have in realising his public-service agenda; and his vulnerability should the cabinet split, as is entirely possible, over British involvement in a non-UN sanctioned attack on Iraq.
These include a live sketch contrasted with its own storyboard, to tongue-in-cheekily demonstrate the difficulty of realising the trio's creative vision; and a job interview where all parties are distracted by the candidate wearing a brooch.
"Its strangeness, its oddity, and the difficulty of realising it scared me".
However, the approach is underutilised in the bioprocess industry due to challenges including lack of accessible tools to support a structured approach, the difficulty of realising computationally tractable (low parameter) yet realistic models, and the specialised skill sets required.
A successor with the same ideas might have more difficulty realising them.
