HELIOS Tech Info #216

Error saving InDesign files introduced with Apple Updates macOS 15.7.8 and 26.6

The recent Apple Security Updates introduce the problem that Adobe InDesign issues an error when saving files on an AFP volume.

The problem started with the Apple Security Updates, other applications are not affected.

The Adobe InDesign error message upon saving:

“InDesign is unable to save this file. We tried, but it appears to be damaged.”

HELIOS has started tracing the save operation, so far no problem has been detected in our software, it must be a macOS or Adobe problem. What is strange in the tracing: it does not show any writing into a hidden temp file which is later renamed to “Untitled.indd”.

Tested servers:

• HELIOS AFP servers (tested using the latest G8 updates)
• Apple AFP servers (tested using macOS versions supporting AFP)

Affected macOS clients:

• macOS 15 starting with update macOS 15.7.8
• macOS 26 starting with update macOS 26.6

Affected macOS application:

• Adobe InDesign 2026 (latest version as well as older versions)

HELIOS recommendations:

• Don’t install these Apple security updates until a solution is known
• Contact Adobe for support because they are responsible for InDesign

We will update this Tech Info, once we have new information regarding this problem.