YouTube cofounders Chad Hurley and Steve Chen are parting ways. The duo worked together for 15 years, starting at PayPal, then got $1.65 billion from Google. But faced a series of missteps at their incubator Avos Systems. Now Hurley is cutting his losses and focusing on just one Avos product, MixBit, and Chen is joining Google Ventures as an entrepreneur-in-residence.

One success never guarantees another: Chad Hurley, who helped bring the world YouTube, is bombing once again. His video-sharing service MixBit is dead following legal threats by Kanye West, and the parent company, Avos, is firing almost everyone. Updated:

As we mentioned earlier this week, Kanye and Kim are suing YouTube creator Chad Hurley for the allegedly unauthorized upload of their lavish, geek-studded proposal ceremony. Now we've got the full legal documents, and they go out of their way to call Hurley a loser.

After Chad Hurley and Steve Chen invented YouTube, they walked away with a bundle of cash and got to work making new websites. Unfortunately, these websites were the exact opposite of YouTube, in that no one wants to use them—now another is headed to the junk pile.

The last time we checked in on AVOS Systems, the company launched by YouTube cofounders Chad Hurley and Steve Chen, morale was bottoming out, the venture couldn't find its way out of the red, and a former employee called it a "gigantic waste of money." Now, the company has launched Wan-Pai, which even TechCrunch admits is a Chinese "clone" of Vine, Twitter's six-second video sharing sensation.

From the tip box, an anonymous AVOS alum has nothing nice to say:

YouTube made Chad Hurley and Steve Chen rich as Saudi kings after they sold it off to Google. They had the chance (and money!) to build anything they wanted—and they did, a brand new company called AVOS Systems. Two years later, and it seems the YouTube duo were a one hit wonder.