If your MacOS has been formatted using MacOS Extended (Case-Sensitive, Journaled) ON1 PHOTO RAW 2019 will fail to load the ONPhotoRaw.framework and this will cause RAW photos to fail to load in the application.
Errors will occur trying to load RAW photos. The following is an example of errors that will appear in the application's log file.
The only workaround is to format your Macintosh HD in MacOS Extended (Journaled)
This is the default format for MacOS.
Supported MacOS Format
Unsupported MacOS Format: