How to fix Photoshop's 'could not complete your request because of a program error' problem
Corrupted program files The error can occur on any Mac but seems to happen more often on a Mac that runs macOS Catalina or macOS Big Sur. This problem is also not unique to macOS, either — as it turns out, Windows users are suffering too. For both Windows and macOS users, the error often occurs when users attempt to create a new file or open an existing one. However, some users note that it has happened when performing certain functions in Photoshop, such as merging layers or applying filte...
Source: appleinsider.com