The nppcrypt plugin can not be updated. It opens up a dialog (Plugin manager) that says:
[It has not been possible to validate the integrity of the "NppCrypt.dll" needed to install or update the plugin. Do You want to copy this file anyway (not recommended)]
I am using npp version 6.6.7. I do not know the previous version of the plugin. Also the encrypted file starts with SALTED__...
Is there a document that explains the format of the encrypted file?
Having this same problem trying to install the latest version 18.104.22.168.
I found the old versions on the developers website.