error 401 Pro version 12.16.3.574

[MichaelGr 0]

Hello, I have read many posts and tried everything,  the sign out - sign in,  the repair, and complete uninstall and reinstall.  still get the error 401 no matter what.  Thanks

[AllainU 0]

Hello @MichaelGr,

Thank you for reaching out to us through our Community Forums!

Let us try some troubleshooting by referring to these steps:

1. Open your Nitro Pro and log out from your Nitro Sign by clicking the drop-down arrow and selecting Logout. This should be below the 'X' Close button of your program.

2. Clear the content of the directory under C:\users\your_username\Appdata\local\temp. For whatever reason, not all temp files automatically remove themselves and is NOT usually caused by Nitro Pro files. Kindly note Appdata folder is hidden and to unhide it, please refer to this article https://cybertext.wordpress.com/2012/05/29/cant-see-the-appdata-folder/ 

3. Download and run our Clean Up utility to uninstall your Nitro Pro:  http://install.nitropdf.com/professional_12163574/install-cleanup/install-cleanup.zip 

NOTE: This clean-up tool will erase any existing signature files within Nitro so please save them to another location before using the clean-up tool in order to keep them. Please see this link for backing up custom stamps/signatures: https://kb.gonitro.com/knowledgebase#/search/stamps/000004307 

4. Clear all your downloads folder or delete all downloaded Nitro installers. This step is important because we noticed that if you are saving all the installers and you download them in the same folder (like the downloads folder), the EXE can pick up any MSI installer in that folder and you may pick-up one of the older builds instead of the newly downloaded package.

5. Download and install Nitro Pro 12.16 using below offline installers:

x32 http://install.nitropdf.com/professional_12163574/en/retail/nitro_pro12_ba_x86.msi 
x64 http://install.nitropdf.com/professional_12163574/en/retail/nitro_pro12_ba_x64.msi

To know if you have 32-bit or 64-bit, please refer to this article:  https://support.microsoft.com/en-ph/help/15056/windows-32-64-bit-faq 

6. After installation, you can activate by opening Nitro Pro, clicking on the Help tab > About Nitro Pro > Activate by entering your serial number

7. Log in back to your Nitro Sign by clicking 'Log In' button.

Thank you for choosing Nitro and I hope this helps.