Viewers had been expectantly tuning in to see if Doncaster man Adam Aveling, 26 and his bride Tayah Victoria, 25, are still an item on the show which sees complete strangers tie the knot.
But TV bosses were left red-faced after the channel repeated Wednesday’s episode rather than the cliffhanger finale.
The channel blamed it on "ongoing tech issues" after a fire alarm at a broadcast centre resulted in several channels going off air on Saturday.
Channel 4 said its services were also experiencing problems with sound and subtitles.
E4 said it would provide an update when it knew when the last episode of the season would be shown.
In a statement on Twitter, E4 said: "We're aware it's yesterday's episode of #MAFSUK playing out this evening and apologise. It's all down to our ongoing tech issues which we're working hard on. We'll update here as soon as we know more and when you'll be able to see the final episode of MAFS UK."
It later tweeted that the finale would not be shown on Thursday.
Channel 4, Channel 5, BBC, ITV, Paramount Network and E Music were among those who were affected by the fire alarm.
Red Bee Media blamed an "activation of the fire suppression systems" at its broadcast centre in west London at the time.
A Channel 4 spokeswoman confirmed the technical issues it was still experiencing were linked to this problem.