Adobe Systems has been forced to take action after Creative Cloud graphics service started deleting delete important user data from its Mac users, for no apparent reason.

The deletions took place without warning or permission and seem to have been triggered after users of the Mac version of Creative Cloud had logged in after a new update to the service had been installed.

The problem was reported by data backup service Backblaze which posted a warning to users on its web site, outlining the root of the problem. On signing in to the Creative Cloud, Mac users of the cloud services were somehow activating a script that deletes the contents of the first folder in the Mac’s root directory, which is prioritised by alphabetical order. This was a particularly bad problem for Backblaze users, because the first folder liable for deletion on their service would be a hidden root folder called .bzvol which contains critical information. The hierarchical naming scheme used to identify this folder happened to coincide with the priorities of the rogue deletion script, so the Mac user’s most important files were deleted first.

Backblaze technical support has issued a Youtube video to explain the phenomenon to puzzled users after social media outlets such as Twitter began to register large numbers of complaints about unauthorized data deletions. The problem could be even worse for other users, who don’t use Backblaze, since the first folder in line for deletion in their Mac root drive would be DocumentRevisions-V100. This is a folder that stores data required for the Mac autosave and Version History functions to work properly. The loss of these contents could leave creative users with severe version control problems and the loss of work which they would have assumed would be automatically saved.

In other circumstances the bug will delete any folders with spaces in the name, which would automatically appear at the top of the listing.

Adobe said it is stopping the distribution of the update until the issue has been resolved. The version causing the deletions is 3.5.0.206. Adobe has warned Creative Cloud users to delay any updates for the time being.