How to Open HEIC Files in Photoshop
'Could not open the file because the format is not supported' — when Photoshop says this, the problem usually isn't PS itself but version and system codecs. Here are the version requirements and two ways out.
Version requirements
Photoshop has supported HEIC since 21.0.1 (late 2019), together with Camera Raw 12.0.1+. Older releases — CS6, early PS 2019 — have no official path; don't burn time on them.
One more step on Windows
Windows additionally needs the HEIF Image Extensions codec from the Microsoft Store before PS can decode HEIC. Offline or corporate machines that can't install it stay broken. On Mac the system decodes HEIC natively, so errors there are almost always version issues.
When you can't install anything
The easiest workaround: batch-convert the HEIC files to JPG in a browser first (this site's tool, nothing uploaded), then edit in PS. At 90%+ quality the impact on retouching is negligible and your workflow doesn't change.
Lightroom and the mobile apps
Lightroom Classic and the cloud version are bound by the same Camera Raw requirement. On iOS, the mobile Photoshop and Lightroom use the system decoder and open HEIC without any friction.