The city’s computer system to register for monkeypox vaccinations suffered yet another high-profile meltdown on Tuesday.

The latest setback for The Department of Health and Mental Hygiene left desperate New Yorkers frustrated and confused.

“This service is not available” read a message that greeted users attempting to nab slots for the much-coveted inoculation.

The site was down for nearly an hour after the registration opened — and crashes and massive delays continued to plague the system throughout the day.

“Due to high level of traffic, the scheduling site is currently down. We are aware of this issue and working to restore it quickly,” DOHMH wrote on Twitter.

The launch was the third round of sign-ups offered by officials — and the third effort that’s been plagued by computer problems as many gay New Yorkers scramble to get the shots.

“Aaaand the website crashes immediately. Who could have predicted this? a: EVERYONE,” tweeted Councilman Erik Bottcher (D-Manhattan), whose district includes the heavily LGBT neighborhoods of Hell’s Kitchen, Chelsea and the West Village.

“Honestly, this is why people think government can’t competently execute simple tasks.”

Bottcher was joined by Councilmen Chi Ossé (D-Brooklyn) and David Carr (R-Staten Island) in calling for the City Council to hold an oversight hearing into the city’s monkeypox response.

“Monkeypox is spreading rapidly in the gay/bi/[men who have sex with men] community and while the primary issue is the federal government’s failure to provide us with adequate vaccine supply,” the three lawmakers wrote, “…the City cannot afford to make missteps.”

Meanwhile, officials quietly confirmed to Politico New York on Tuesday that DOHMH had switched the contractor in charge of running the vaccine appointment and distribution program from MedRite to Affiliated Physicians after a series of computer signup problems during the first two rounds.

The website signup provided by AP appeared to be identical to the system the company used during the signups for COVID vaccinations, which also repeatedly crashed on heavy demand.

Those continued problems prompted the then-de Blasio administration to have staff build an in-house computer system to handle vaccine registration for the myriad of city-run sites across the Big Apple, Vax4NYC.

DOHMH and City Hall did not immediately respond to questions from The Post about the AP contract.

Tuesday’s computer system fiasco was the latest in a long line of problems that have plagued the local and federal response to the monkeypox outbreak in New York City and across the country.

It comes as the case count in New York City grew again, totaling 267 patients. That’s up 20% from the 223 case total on Monday — and more than double the 111 reported just seven days ago on July 5.

Pressure is mounting on local and federal authorities to overhaul their response to the monkeypox outbreak as cases continue to surge amid inoculation shortages, a problem-plagued computer signup system for shot appointments and widespread complaints about accessing testing and anti-viral medications to manage infections.

The fiasco comes just hours after Mayor Eric Adams told President Biden in a letter sent to the White House on Monday that New York “urgently” needs more vaccines.

New York City has received just 7,000 doses of vaccine so far — with roughly another 14,500 set to be delivered in the coming days.

But that stock of 21,000 doses is enough to fully vaccinate roughly 11,000 New Yorkers, which health officials have admitted is woefully insufficient for the expected demand or to curtail the outbreak.

LGBT and public health activists have blasted the Biden administration for blocking the importation of more than 1 million ready-to-ship doses of vaccine already paid for by taxpayers at the manufacturing plant in Denmark after the US Food and Drug Administration failed to inspect the plant.

The FDA has refused to accept the results of a comparable inspection performed by regulators in the European Union, which the facility passed.

The Biden administration has referred questions about the inspection to the FDA, which has declined to provide any details about if the inspection is underway or when it will happen if it is not.