Paw Patrol's Skye and Marshall did not appear at a Christmas lights switch on in Londonderry on Thursday night.
Derry City and Strabane District Council has since apologised.
Broadcaster Nickelodeon said they had not "organised or authorised" the use of the characters at the event.
Nickleodeon's Paul Hamilton said there are no official PAW Patrol appearances anywhere in the UK or Ireland at present.
The character's appearance had featured prominently on pre-event promotion.
Derry City and Strabane District Council marketing officer Jacqueline Whoriskey said every effort was made to secure Skye and Marshall,  and that the council was " sorry to disappoint people".
She added: "We were contacted very late in the day by the official licensee in America to say that the company we were using did not have the appropriate licences.
"We tried our best to resolve it in time - unfortunately it didn't work out - and are really, really disappointed".
Strabane's Christmas lights will be switched on on Saturday but Skye and Marshall will not be there.
They had been due to share top billing with Santa Claus.
Despite the PAW Patrol no show, thousands gathered in Londonderry's Guildhall Square and Waterloo Street for Thursday night's switch on.
Characters based on a Nickelodeon cartoon were dropped from a Northern Ireland council's Christmas celebrations - after it emerged they were unauthorised.