A retired couple were turned away from a dream £4,000 cruise after their NHS Covid app suddenly stopped working.
Malcolm Walker, 75, and his wife, were due to embark on a long-awaited cruise from Southampton to Portugal, Spain and Gibraltar - having travelled down from Scotland.
However, on April 18, Malcolm was left "astounded" when his NHS Scotland Covid status app underwent a "security update" just moments before his trip.
The security update meant he could not access his vaccination status which proved Michael and his wife had been triple-jabbed.
Mr Walker claims staff refused to let them board the ship and says he is around £3,800 out of pocket for the cruise, insurance, car parking, hotels having travelling down from Scotland to Southampton.
He said the app had been working the day before they were due to set sail and has demanded an apology from the Scottish Government.
Mr Walker told DailyMail.co.uk : 'Two days before and the day before I checked the Covid-19 status on my mobile phone and all was well until we reached Southampton.
"The verification level on my iPhone 6 was level 11.4, my wife's 12.1.
"On the day of departure, NHS Scotland increased the verification level to 13.1.
"As our phones are older with the information permanently stored, we had no need for the user name or password, and there was no prior warning - we were completely unaware of anything amiss.
'Preparing to board, we were astounded to find that we could not access the app, so we were denied access to the cruise."
Malcolm had previously tried to acquire paper copies of his vaccination status - but they said because he didn't have his wife's email address they could not give it to him.
He tried their helpline but had no response and assumed his app would work for the cruise.
Malcolm added: "This affair has cost me a lot of money.
"We have been in touch with our insurance company, but feel it is unfair for them to recompense us when the fault lies with the Scotland's NHS department and Government...I would like an apology.
"This happened because they did not inform people of their intentions, but upgraded, and altered the app without thought or consideration as to the possible consequences."
Responding to Malcolm's claims, a Scottish Government spokesperson said: 'We are sorry to hear of Mr Walker's experience.
'In common with all apps available on the iStore, the NHS Scotland Covid Status App is only available on phones which receive vital security updates and works on all Apple phones released since 2015, providing the user has updated the operating system to at least iOS 13.1.
"A recent routine security update required by Apple removed unsupported operating systems from being able to support the app.
"Anyone unable to use the app can get a paper copy of their vaccination certificate online or via the Covid Status Helpline on 0808 196 8565."
Due to Portugal and Spain's Covid travel restrictions the retired couple would have been required to prove they were fully-vaccinated.