Pokemon GO Fest takes place today at Grant Park in Chicago, IL. The event is meant to be a way for players to celebrate the game’s anniversary with thousands of other fans, allowing them to catch ’em all together (including regional Pokemon.) But unfortunately, the event is not going as smoothly as developer Niantic will have hoped.

Players attending Pokemon GO Fest are reporting that they are unable to play the game as intended. Pokemon GO Fest offers special Gym areas and there are also PokeStops at Grant Park too, but players say that they are unable to log-in to the game and access them or catch any Pokemon. According to reports on social media, the technical issues have been ongoing for several hours and seem to be getting progressively worse, likely due to the influx of fans arriving at the event.

Understandably, the many Pokemon GO fans in attendance are furious. When Niantic CEO John Hanke walked on to the stage, he was booed by unhappy players. At one point players began to chant ‘fix the game’ whenever Niantic employees walked on to the platform.

Niantic, for its part, is obliging. The developer has assured Pokemon GO players that it is aware of the technical issues and is currently working on a fix. While fans appreciate the effort, many disgruntled fans are asking why Niantic did not test its game appropriately to prevent this from happening. Pokemon GO faced technical issues earlier this week and in Game Rant‘s own reporting, fan concerns about Pokemon GO Fest server stability were highlighted. Niantic was seemingly unwilling or just unable to heed those warnings.

At this point it is unclear when Niantic will have a solution ready. The first Pokemon GO Fest challenge was meant to have started half an hour ago (as of the time of writing) and had an end time of 11:30AM CDT. The first three challenges are running on a pretty strict timetable, with less than two hours between each one, but Niantic has not stated how it will factor in these technical difficulties and whether it will be more lenient in the challenge victory conditions.

Another big question is how this will affect the introduction of Pokemon GO legendaries. The plan was that Pokemon GO players were meant to complete the first three challenges and a get gold rating to unlock the legendary characters, but this may not be possible because of the server issues. Fans are now fretting that they will be unable to earn the legendary gameplay content and Niantic will also need to clarify things to concerned fans when it releases that fix.

Pokemon GO is available on iOS and Android.