Disney's new streaming service is straining under the load as users rush to log in to the highly anticipated service on its US launch day. Frustrated users took to social media to complain about seeing "unable to connect" error screens instead of the Star Wars, Marvel, and Pixar movies they were hoping for.

"The consumer demand for Disney+ has exceeded our high expectations," Disney tweeted on Tuesday morning. "We are working to quickly resolve the current user issue."

Disney is aiming to reshape the paid video streaming landscape with its Disney+ offering. Until now, a lot of online streaming has been done on independent services like Netflix and Amazon Prime Video.

With Disney+, Disney is seeking to cut out the middleman and stream its content directly to customers. The company's vast library of movies and television shows, bolstered by last year's acquisition of 21st Century Fox, will make the service immediately attractive to millions of potential customers.

But of course the product will only be attractive if it works reliably. Disney is building its streaming service using technology developed by BAMTech, a company formed by Major League Baseball teams to stream baseball games. In recent years, the company has expanded to support everything from professional wrestling to HBO Now (though HBO recently cut BAMTech loose).

Disney acquired a majority stake in the company in 2016 and started to use it for the streaming service of Disney-owned ESPN. Now it serves as the foundation for Disney+.

The outages come despite extensive preparations by the BAMTech team—now known as Disney Streaming Services.

"We’re thinking very much about" overloaded servers, said Michael Paull, the head of Disney's streaming efforts, in an August interview with the Verge. Paull has been the head of BAMTech since 2017 and before that was a vice president at Amazon's digital video team.

"Fortunately, we’ve had the experience with Game of Thrones, we’ve had the experience of ESPN+ with the big pay-per-view events that we’re doing with UFC exclusively on our platform," Paull told the Verge in August. “We are ready. We’re spending a lot of time planning for this launch.”