Adobe has patched its Creative Cloud apps after people noticed the software was deleting Mac users' files without warning.
After customers updated Creative Cloud, it accessed their hard drive and deleted the first folder that appeared in alphabetical order.
Due to file-naming conventions on Mac computers, the bug often deleted hidden system folders or data backup files.
Adobe issued a fix for the issue on Sunday.
Many people in the creative industries have reacted angrily on social media.
"So Creative Cloud is what screwed up my Backblaze backups. Thanks, Adobe," said college instructor JJ Litke.
"I think Adobe owes us an explanation, and owes Backblaze a public apology. This bug is disturbing and terrifying," tweeted Funjon.
"Great news that fix is out but very disappointed Adobe haven't been very transparent or apologetic about the issue," said another user.
The problem came to light on Thursday after Backblaze, which makes data backup software, started receiving hundreds of support requests from its customers.
The firm's software detected that some of the files it uses to perform its duties had been deleted, and staff discovered that Creative Cloud was responsible after a designer installed Adobe's update.
The issue was present in Creative Cloud version 184.108.40.206 on a Mac.
"We kept testing and realised that this was occurring upon 'sign-in' to Creative Cloud," Backblaze said on its blog.
The company later identified the Creative Cloud bug was deleting the first folder that appeared on the hard drive in alphabetical order.
On a Mac, hidden files and folders are prefixed with "." which the operating system places before A in alphabetical order.
The flaw interfered with Backblaze's software by chance because the backup software places a hidden folder called ".bzvol" on the hard drives it indexes, which happened to be top of the list.
On machines without the backup software installed, a different folder may have been deleted instead.
"As someone affected by this bug I am pretty annoyed. Materially it hasn't (yet) cost me any work, but it's a huge violation of trust," said one user on Reddit.
In a statement, Adobe said: "On the 12 Feb we were notified that some customers had an issue with an update to the Creative Cloud Desktop application.
"We removed the update from distribution and deployed a new one which addresses the issue."