Device noise profiles built with previous versions of Neat Image can, with certain limitations, be used in the current version. Building new profiles directly with the current version is of course preferred (this may potentially provide a higher accuracy) but, if necessary, older profiles can be converted to the new format using the Profile Converter tool.
The Profile Converter is a dedicated tool that can automatically convert several noise profiles built with Neat Image v2.1-3.1 and v4.x to the new format of Neat Image v5.0. Only those profiles can be converted that contain embedded noise samples. Use the Profile Viewer, accessible via the Ctrl+I shortcut or the Profile | Profile Viewer menu item, to check whether a profile contains embedded noise sample.
As the result, you have a set of converted noise profiles (several new *.DNP files on the disk) that can be directly used in the current version of Neat Image.
If you open an older profile, Neat Image will try to automatically convert it before use. This however takes additional time during opening a profile and it may be better to convert all profiles using the Profile Converter: you apply it once and then use converted profiles with no conversion overhead.