More than one year after launching a Kickstarter for a stylish, high-end hoverboard called Moov, Mark Cuban-backed Radical Transport has disbanded, refunds have been issued to backers, and the product is indefinitely shelved.

The reason? “Patent issues,” Cuban told The Verge in an email. “Everyone wanted to sue everyone. I just didn’t think it was worth it.” The billionaire CEO declined to specify who he meant by “everyone,” but the fight over hoverboard patents is not new, and it revolves around just a few players.

Shane Chen — founder of a company called Inventist — is listed as the inventor on the patent associated with the most popular style of hoverboard. One of the keys to Chen’s patent is that it covers the split in the middle of a hoverboard, which allows the two opposite sides to twist as the rider applies pressure in order to change speed and direction.

Chen used this innovation to make and sell a hoverboard called Hovertrax. When a wave of hoverboard knockoffs from China started to flood the market in the United States in 2015, Chen used his patent to keep as many competitors at bay as possible. It wasn’t enough to keep all of them back, but it was a strong enough foothold that toy company Razor eventually decided to buy the rights to the Hovertrax. The company then took up the bulk of Chen’s legal battles.

Razor didn’t get the rights to the patent easily, though. Cuban tried to strike a deal with Chen in 2015 when hoverboards were still hot (though not explosively hot — yet), but eventually relented because of the swelling legal drama. He told BuzzFeed at the time he’d decided instead to create a new hoverboard that “respects necessary IP and introduces our own.”

Two years after making that promise, a small company called Radical Transport — backed by Cuban — came out of stealth promising an evolved take on the idea of a hoverboard that didn’t twist in the middle. Instead, it used sensors to measure the flex in the board and translated those inputs into movement.

The board also featured bigger wheels, a wider base, premium materials, and a cut-out handle for carrying it around. It was supposed to have swappable decks with different styles and colors, and a smart, fully featured mobile app, too. Where other hoverboard companies had pushed to drive down the price, sometimes by sacrificing safety, Radical Transport decided to go high-end — a strategy that was reflected in the $1,300 price tag.

Radical Transport launched the Moov, as it was called, on Kickstarter last summer. The company, which consisted of just three people, raised $75,038 and promised the Moov would ship by the 2017 holiday season. (Asked last year why he chose to use Kickstarter, Cuban responded: “Why not?”) On August 22nd, Radical Transport announced it had struck a deal with a third-party company to handle assembly and shipment. At that point, it still looked like the Moov was on track.

One week later, though, an inventor named Daniel Wood was granted a patent for a very similar idea. Wood is currently employed by Future Motion, which makes the OneWheel — a self-balancing vehicle that operates like a single-wheeled skateboard — and was also involved in the development of other self-balancing rideables like the Hovetrax and Solowheel, he told The Verge. Wood also developed a self-balancing unicycle with his own company, Focus Designs, nearly a decade ago, and even appeared on Shark Tank to pitch the idea.

Wood told The Verge that he spent years developing his no-pivot version of the hoverboard after having experienced a fallout with Chen, and that he “tried several times to make a deal with Cuban” before and after his patent was granted, though to no avail.

Wood’s patent might not have been a roadblock for Radical Transport, according to EJ Williams, the former vice president of engineering. Instead, Williams said in a message, this was just a case of unfortunate timing. “Since [the hoverboard’s] popularity happened overnight, everyone filed patents around the same time,” he wrote. “But since you can’t see or find a patent that is pending... then you don’t know what the other people are pursuing as patents until a year or so after they ‘drew their line in the sand’ and claimed a certain technology as theirs.”

Cuban, meanwhile, said Radical Transport does have the right IP needed to make and sell the Moov, but that he doesn’t see the company “activating it” any time soon. He just “didn’t want to be the one who fought all the battles,” he said.

Whatever the case, Radical Transport announced in late November that it was “in the process of evaluating a partnership” that would allow the company “to make an even better Moov than originally designed,” but didn’t say anything after that. Radical Transport’s three employees — Williams included — have all left the company for new ventures, according to LinkedIn. Its social media channels have been dormant for months, and the company’s domain name has been taken over by a scam effort purporting to be Time Warner Cable, a cable television service that no longer exists.