MacBook owners have been complaining about Apple's butterfly keyboard for years. Here's how the problems unfolded.

Apple launched its super-slim new laptop, simply called MacBook, in 2015. It famously included just one USB-C port and was the company's first laptop to come with the new butterfly keyboard.

Later during that same year, some 12-inch MacBook owners began reporting in Apple's Communities forums that they had been experiencing unreliable space bars and sticky keys.

Following the launch of Apple's MacBook Pro in 2016, which saw the debut of the Touch Bar, customers continued to report keyboard problems.

In a Reddit thread from roughly two years ago, MacBook Pro owners posted that certain keys would intermittently get stuck during use. For some users, this impacted alphanumeric keys, while others reported that the space bar was affected.

Similar comments about the 2016 MacBook Pro were also published in Apple's Communities forums.

In a piece titled "The New MacBook Keyboard is Ruining My Life," The Outline's Casey Johnston described an issue with the spacebar on her MacBook that caused it to register two spaces instead of one when tapped. The piece also delved into how the butterfly mechanism works and reflected her frustration with issue, as she mentioned visiting the Apple Store three times in an attempt to fix the problem.

Meanwhile, customers continued to report faulty keyboards throughout 2017 on Apple's Communities website and on MacRumors in its forums section, as the website pointed out in February of that year. The problems seemed to echo the previous complaints, with some users saying that certain keys stopped working, and others reporting that a key would register two presses for every one press.

YouTuber Jonathan Mann, who has been writing a song every day for 10 years, published a tune parodying Apple's butterfly keyboard called "I Am Pressing the Spacebar and Nothing Is Happening."

The video shows Mann pushing the space key while the cursor on screen remains in the same place. He also touches on the tips Apple provides on its website, which include holding the laptop at a 75-degree angle and using compressed air to clean the keyboard.

The video now has 223,370 views and Mann's YouTube channel has 39,000 subscribers.

A petition on Change.org urged Apple to recall every MacBook Pro released since late 2016. It also called for the company to replace the current butterfly keyboards with new redesigned keyboards "that just work."

The petition was published in May 2018, as a report from 9to5Mac indicates, and it currently has more than 36,000 signatures.

Apple was hit with a class action lawsuit last May over the issues customers have been experiencing with its butterfly keyboards. The complaint reads:

"The MacBook Pro is marketed and sold as top of the line — the 15-inch model's starting price is $2,399. But the MacBook is defective: it's butterfly keyboard is prone to fail. Thousands of consumers have experienced this defect. When the MacBook's butterfly keyboard fails, the keys stick and no longer register keystrokes. As a result, the user cannot type."

Apple launched its Keyboard Service Program last June to address the reported issues that have surfaced over the years. As part of this program, affected customers can get their keyboards fixed, free of charge, by visiting an Apple Retail store or Apple Authorized Service Provider, or by mailing their laptop to the Apple Repair Center.

Apple released its most recent MacBook Pro in 2018, which brought faster, 8th generation Intel processors, Apple's T2 security chip, and a new third-generation butterfly keyboard among other updates. Apple would later bring its latest iteration of the butterfly keyboard to the new MacBook Air in October 2018.

But as the Wall Street Journal noted last month, the previously reported keyboard issues have continued to persist, even on the third-generation version.

Following Apple's MacBook Pro launch, iFixit discovered that the butterfly switches in the third-generation keyboard are coated in a silicon membrane, which the website speculated could have been a measure to prevent dust from creeping into the device.

That theory was seemingly confirmed days later when MacRumors reported that an internal Apple document confirmed this silicon was indeed intended to keep debris from entering the keys.

Apple released a statement on March 27 in which it apologized to MacBook users impacted by issues with its butterfly keyboard. The Wall Street Journal first reported the statement in a column highlighting the problem.

"We are aware that a small number of users are having issues with their third-generation butterfly keyboard and for that we are sorry," Apple said in its statement. "The vast majority of Mac notebook customers are having a positive experience with the new keyboard."

Prominent Apple blogger John Gruber called Apple's butterfly keyboards "the worst products in Apple's history" in response to the Journal's column.

David Heinemeier Hansson, chief technology officer at Basecamp and creator of the popular web application framework Ruby on Rails, tweeted about the issues his company has been facing in regards to Apple's butterfly keyboard.

"Nearly half of all the 3rd-generation, membrane-enhanced keyboards in the 2018+ MacBooks are failing at Basecamp," he wrote. "This is not a 'small number.' It's a catastrophe and Apple should do a total recall."

Hansson followed up by conducting a Twitter survey, which indicated that 53% of the 7,577 respondents said they are experiencing keyboard issues but are "living with it." Eleven percent of respondents said they encountered problems but Apple repaired them, and 36% reported that their keyboard is perfect.