After activating Microsoft NTFS for Mac by Paragon Software you get a “Failed to validate license data” error.
Typically, this error occurs when using an incorrect licence key, e. g. a serial number not belonging to the product you are trying to activate. Most likely you are using a license key for NTFS for Mac 14 that you purchased before.
This key cannot activate Microsoft NTFS for Mac by Paragon Software.
Please check your MyParagon account for the licence for Microsoft NTFS for Mac by Paragon Software or if you are eligible for an upgrade in “My Upgrades“.
Repeat the activation using the serial number of Microsoft NTFS for Mac by Paragon Software.
CR: Activation, Known issues during activation, NTFS for Mac OS X