Hi, I’m a type designer and font delveloper (for more than 20 years) and have made a custom font (Latin) that makes extensive use of the Contextual Alternates feature (calt). Let's call the font FontXyz, it’s an OpenType CFF font (.otf).

These are the steps that always cause InDesign to crash
1: Text cursor is in an empty text box where my FontXyz is already set
2: Pasting the string “1234,-”
3: Crash

I can prevent the crash by:
a: Putting my cursor in between two spaces and then pasting the string “1234,-”
b: Pasting the string without the “-”, thus pasting “1234,”

The font has passed various validation tests (Fontbakery (even the “check-adobefonts” one), FontGoggles, Font Validator) and works without any issues in other MacOS apps (such as Microsoft Word, Pages, Figma and browsers).

The crash occurs in Adobe CC InDesign 2024 and 2025
I'm running MacOS 15.5

(Why is the button to submit this bug report called “Post idea”, it really should be “Post bug”)