Until this past weekend, Pokémon Go was only available in a few countries, including the U.S. So when Niantic and Nintendo finally launched the mega popular mobile game in 26 more countries on Saturday, players were probably super excited… and then servers started crashing, causing more headaches than monster-catching glee.

Niantic has had a hard time keeping up when people in 26 more countries started downloading the app, with reports of outages and server problems cropping up almost immediately on Saturday.

The company addressed the issue on Twitter through the Pokémon Go account, telling users it was working to fix server issues and would keep folks updated:

Niantic posted a similar message on its web site, writing:

“Pokémon GO downloads, some Trainers are experiencing server connectivity issues. Don’t worry, our team is on it!”

By the next morning, the server issues had been identified and fixed, the company said:

While Niantic hasn’t announced what caused the server issues — perhaps a huge digital horde of Pokémon fans all downloading and trying to play the same day at one time? — a group of hackers has claimed to be behind the outages, Tech Times reports.

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