Fan charity Gol Cymru was looking to build on the success of its parties held either side of Wales' opening World Cup game against the USA with a second round of events for Friday's fixture with Iran.
But they said they were told at the last minute of new conditions preventing alcohol sales before 12pm, leading to them cancelling their pre-match event at the InterContinental Doha hotel, in the West Bay area of the city.
The Wales Football Supporters' Association's fan embassy later noted Friday is a holy day and "no alcohol before midday" is allowed.
Wales' crunch group B fixture against Iran kicks off at 1pm Qatari time, 10am in the UK, at the Ahmed bin Ali Stadium.
The sale of alcohol to fans at World Cup stadiums in Qatar was banned two days before the tournament kicked off - with an exception made for corporate spectators.
The UK Foreign Office said it is an offence to drink alcohol or be drunk in public, with alcohol available at designated places including hotels.
Gol Cymru fundraiser and organiser Leigh James told fans in an email: "The hotel have been in discussions with the Qatari authorities overnight and unfortunately, as it is with Qatar, a change has been imposed and we can now no longer serve alcohol before midday Friday.
"Therefore, we have had to take the decision to cancel the pre-match event and offer you two options."
These include attending a post-match party on Friday, or a pre-match party on November 29 before the final group B game with England.
Mr James added: "Once again on behalf of the hotel I apologise, however I have learnt that in Qatar to always expect the unexpected."
He went on: "Please understand this is Qatar and many things are totally out of my control, I am frustrated as the next person when they make last-minute decisions."
Paul Corkrey, from the Wales Football Supporters' Association (FSA), said the pre-match party was a "great place" for people to congregate ahead of the 1-1 draw with the USA on Monday and fans were "pretty sensible" travelling to the game.
He said it was "disappointing" to hear the changes imposed on Friday's pre-match event, telling the PA news agency: "There's one thing about it - they are consistent, they consistently change the rules.
"There's not a lot we can do, really, just say that we're disappointed really.
"A lot of fans are by themselves, in ones or twos, and they go to these things for company and be with their friends or to meet new people."
Mr Corkrey said fans are "having a great time everywhere else", adding of the Qatari authorities: "It's such a shame as the facilities, the place, the weather, the fact you can see three or four games in a day, is positive.
"But they keep doing negative things now and then."
Elsewhere, England fans urged Fifa to avoid a repeat of the ticketing problems which meant some missed parts of the Three Lions' opening game 6-2 win against Iran.
Some supporters were frantically refreshing the official ticketing mobile app on their phones in a bid to have their QR code load just minutes before kick-off.
Ashley Brown, from the FSA's fans' embassy, said: "This issue is well documented and Fifa simply has to get on top of it. At the England-Iran game some fans had to queue in excess of two hours to get this sorted.
"Supporters want to know that Fifa are taking this seriously by widely communicating what they're doing to fix the problem and what match-goers should do if it happens to them.
"This needs to be tackled now.
"We'd advise all supporters to arrive early in case of any future issues."
A Fifa spokesman said: "Fifa's service provider is working on solving the issue that some spectators are facing with the Fifa ticketing app as soon as possible, with alternative solutions being provided in the meantime that allow all ticket holders to access the stadium."
The FSA's Mr Brown also commended Germany's protest against Fifa over the OneLove anti-discrimination armband.
Germany's players covered their mouths during a team photo ahead of their 2-1 defeat against Japan to show "Fifa is silencing us" by shutting down attempts to wear rainbow-coloured armbands.
Mr Brown, speaking on behalf of the England fans' group, said: "We're sure that action hasn't gone without notice in the England squad, many of the players have a track record in speaking up on social issues, and we're certain they'd have approved."