Jump to content


Rejean Paquet

Recommended Posts

Rejean Paquet



I am having the 401 Error every time I open Nitro Pro v12.

I followed the link you provided but I get an error message while doing the install. It says Nitro Pro Setup Wizard has failed, then there is a Finish button, that's all.



Link to comment
Share on other sites

  • Official Nitronaut
Allain Umailin

Hello @Rejean Paquet,

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. 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.

4. Download and install Nitro Pro 12.16.9 using below offline installers:

x32 http://install.nitropdf.com/professional_12169574/en/retail/nitro_pro12_ba_x86.msi 
x64 http://install.nitropdf.com/professional_12169574/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 234600-xxxxxx-452671

7. Reset your Nitro Sign password, login back to Nitro Sign by clicking 'Log In' button.

If the error re-occurs after few days, please let me know so we can check our resources.

Thank you for choosing Nitro.

Link to comment
Share on other sites

  • 4 weeks later...
Rejean Paquet

I followed provided instruction, Nitro seems to work fine, I logged out and log back in a few times, I don't see the 401 error. I will pay attention in the next few days, Thanks AllainU for your quick response.

Link to comment
Share on other sites

Rejean Paquet

*Update* today August 23 when I opened a PDF document I got the 401 error. I noticed in the upper right corner of NITRO my name is displayed but I don't see the little squirrel icon. If I  log out then log back in now I can see the little squirrel icon.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.