The phrase "a disappointing development" is correct and usable in written English.
It can be used to describe a situation or event that did not meet expectations or has led to dissatisfaction.
Example: "The announcement of the project's cancellation was a disappointing development for the entire team."
Alternatives: "an unfortunate turn of events" or "a frustrating outcome".
In a statement, NBC News said: "This is a disappointing development.
"This is a disappointing development and it is completely at odds with the recent views of other rating agencies.
Kate Craig at Liberum Capital said: A disappointing development - we had envisaged a bid at around 550p a share versus our net asset value of 418p a share.
Mr. Gore, campaigning in Ohio with his running mate, Senator Joseph I. Lieberman of Connecticut, told reporters, "I think it's a disappointing development".
There is no doubt about it, for those of us in the telehealth industry, this month has seen a disappointing development.
"This is a disappointing development and does not augur well for the maternal and child health indicators of the country," she said.
Sudan's government, led by President Omar el-Bashir, described the United States support for the rebels as "a very disappointing development" and predicted that the additional backing for the Northern Democratic Alliance would lead to "more bloodshed and killing".
"Whilst it is clearly a very disappointing development, our decision provides verification that the rigorous checks we have in place are working and that there is a quality threshold being applied.
"Despite this disappointing development, Hit remains a highly profitable company with one of the strongest portfolios of young children's properties," he said in a statement.
ONE disappointing development in last week's television upfronts, when networks announced their fall lineups, was that there was no real contender for a breakout hit set in the offices of a fashion magazine.
They were the latest of several disappointing developments that included an acknowledgment by Federal Reserve officials that the pace of recovery in the United States had slowed.
