Finland's biggest movie theatre chain Finnkino said its website was still operating very slowly on Thursday.
On Christmas Day technical problems forced Finnkino to close down its online ticket sales.
Tickets can be bought normally at cinemas.
“If you’ve booked a ticket for today, it’s a good idea to head to the theatre well in advance to redeem your ticket,” Finnkino sales director Hannele Wolf-Mannila said.
Finnkino on Wednesday said it suspected overwhelming demand for Disney's Frozen sequel, released on Christmas Day, to be behind the problem.