Dropbox has just issued an apology regarding the extended outage it experienced over the weekend. In addition, as noted by The Next Web, the company behind the popular cloud storage service of the same name offered a postmortem on how the shutdown came about.

As we reported here on AppAdvice, last Friday evening, Dropbox went offline, resulting in its inaccessibility across the Web and its desktop and mobile clients.

While the service was mostly restored several hours later, some Dropbox users continued having issues throughout the weekend. Fortunately, Dropbox is now said to be “back up and running” for all users.

Initial reports suggested that the outage was caused by hacking or a DDoS attack done supposedly in honor of the first anniversary of the death of Internet activist Aaron Swartz. But Dropbox maintains that it was caused by an issue that arose during routine internal maintenance.

On its main blog, Dropbox states:

On Friday evening we began a routine server upgrade. Unfortunately, a bug installed this upgrade on several active servers, which brought down the entire service. Your files were always safe, and despite some reports, no hacking or DDOS attack was involved.

To learn more about what happened and the Dropbox team’s takeaways from the event, read the outage postmortem on Dropbox’s tech blog.