Twitter went down for millions as users reported several issues with the platform -- from links not opening to images stopped loading and more -- as there was only one person handling the platform's application programming interface (API).
When users clicked on links, they were greeted with a mysterious error message reporting that "your current API plan does not include access to this endpoint".
Images stopped loading as well and some users said that they could not access TweetDeck.
About 85 per cent users had trouble with the web version of Twitter while 13 per cent had issues with the mobile platform
In a tweet, the company said that "some parts of Twitter may not be working as expected right now".
The company's support account tweeted, "We made an internal change that had some unintended consequences."
The change in question was part of a project to shut down free access to the Twitter API, according to Platformer.
Last month, Twitter announced it will no longer support free access to its API.
It ended the existence of third-party clients and drastically limited the ability of outside researchers to study the network.
The change had cascading consequences inside the company, bringing down much of Twitter's internal tools along with the public-facing APIs, reports The Verge.
Musk tweeted on Tuesday: "A small API change had massive ramifications".
"The code stack is extremely brittle for no good reason. Will ultimately need a complete rewrite," he posted.
There have been at least six high-profile Twitter outages this year, as Musk has fired thousands of employees, including those handling APIs and codes.