Define Trusted Locations to differentiate safe files from potentially harmful files. When a file is in a trusted location, it’s files are assumed to be safe. If you try to save a file in a location that is not trusted, Reflection warns that it will not be able to reopen the file.
Reflection enforces trusted locations by default, so if you want to save sessions in directories that are not default trusted locations, you’ll have to define these directories or disable the Trusted Locations feature. See Add Trusted Locations.