Background: Blink-182 (often stylized as blink-182; pronounced "blink one eighty two") is an American rock band formed in Poway, California in 1992. Since 2015, the lineup of the band has consisted of bassist and vocalist Mark Hoppus, drummer Travis Barker, and guitarist and vocalist Matt Skiba. Founded by guitarist and vocalist Tom DeLonge, Hoppus and drummer Scott Raynor, the band emerged from the Southern California punk scene of the early 1990s and first gained notoriety for high-energy live shows and irreverent lyrical toilet humor. Blink-182 was initially known as Blink until an Irish band of the same name threatened legal action; in response, the band appended the meaningless number "-182".
Context: Eventually, the band appeared for the first time on stage together in nearly five years as presenters at the February 2009 Grammy Awards, announcing their reunion. The trio embarked on a reunion tour of North America from July to October 2009, with a European trek following from August to September 2010. The recording process for Neighborhoods, the band's sixth studio album, was stalled by its studio autonomy, tours, managers, and personal projects. DeLonge recorded at his studio in San Diego while Hoppus and Barker recorded in Los Angeles--an extension of their strained communication. The self-produced album--their first without producer Jerry Finn--was released in September 2011 and peaked at number two on the Billboard 200. Its singles--"Up All Night" and "After Midnight"--only attracted modest chart success, and label Interscope was reportedly disappointed with album sales.  "Despite growing evidence of remaining friction between the members," the band continued to tour in the early 2010s. They headlined the 10th Annual Honda Civic Tour in North America from in 2011, and toured Europe in 2012. The band left Interscope Records that October, and subsequently released Dogs Eating Dogs, an EP, in December 2012. The trio toured Australia in 2013; Brooks Wackerman replaced Barker on drums as Barker was unwilling to fly after his plane crash. These dates were followed with a small North American tour, and a series of shows celebrating the tenth anniversary of the band's self-titled album that November. The band played a European tour in August 2014, culminating in them headlining the Reading and Leeds Festivals; it was the band's fourth appearance at the festival and second headlining slot.  The reunion of the band has been characterized as dysfunctional by both Barker and DeLonge. Hoppus commented on this era of the band in a later interview: "Everything was always very contentious. There was always just a strange vibe. [...] I knew there was something wrong." In his memoir, Can I Say, Barker claims DeLonge's behavior on tour was "introverted" until "money started coming in," after which "he'd get excited about Blink." He states DeLonge abruptly quit sometime in mid-2014, and rejoined the following day. The group planned to begin writing their seventh album in January 2015, which had continually seen delays. "I'd do interviews and I just felt awful for fans because they were promised albums for years and we couldn't do it," Barker later said. A record deal was finalized and sessions were booked before DeLonge's manager informed the band he intended to spend more time on "non-musical activities" and indefinitely depart the group. In his own statement, DeLonge remarked that he "Never planned on quitting, just find it hard as hell to commit." After these events, Barker summarized the band's reunion: "Why Blink even got back together in the first place is questionable."
Question: What led to them appearing for the first time in five years?. Whats the answer?