In order for me to further assist you with your concern, could you please send me a private message and provide the following?:
-The serial number of your Nitro Pro. This matters because our business installers are different from the online ones.
-Nitro Pro build (format is 12.X.X.X, e.g. 12.0.0.112) you are working with. You can find this out by clicking on 'About Nitro Pro' under the Help tab (format is 12.X.X.X, e.g. 12.0.0.112) or you can go to Control Panel > Programs and Features.
-Does this happen with every file? If it is a single file, please send us the sample file (with sensitive information extracted) so I can replicate it on my end. To send me the sample file, hover your mouse on top of my name 'AllainU' and select 'Message'.