A High Court Judge has ruled that Northern Ireland's environment minister acted unlawfully in approving a new GAA stadium in west Belfast.
Planning permission for the 38,000-seater stadium was granted by Mark Durkan in December 2013.
Local residents who objected to the size of the planned development launched a legal challenge in response.
Mr Justice Horner held that the decision-making process was "fundamentally flawed".
He identified failures in the environmental impact assessment of the increased facilities.
The judge also pointed to the minister never being told of police concerns about safety issues around having 38,000 people attending an event.
However, he did not quash the minister's decision.
Instead, lawyers for the DoE, the GAA and a residents group who mounted the legal challenge are to make further submissions on appropriate remedies.
Mr Durkan said he remained hopeful that "there might be a positive outcome to this".