Problem activating product

[Unnur Jónsdóttir]

Nitro was working fine until recently. I tried to activate it again but when I try it says there was a connection issue, even though I am connected to the internet as I am posting this. 
And if I try to do it manually, it offers an offline activation. But that doesn't work either since I enter my serial number and it gives me these instructions:
Step 1: Copy the pre-generated certificate from below
Step 2: Open http://www.gonitro.com/activation on an internet-enabled device and paste the pre-generated certificate. This will generate new activation certificate.
Step 3: Copy the new activation certificate, return to this window and click 'Next´ to continue activation.
Sounds easy enough except it does not create a pre-generated certificate for me. The box that should have it is empty so there is nothing I can do.
So what can I possibly do to activate my product again?

[Allain Umailin]

Hello @Unnur Jónsdóttir,

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

In order to further assist you, could you please provide a screenshot of your 'About Nitro Pro' window under Help tab? This window should show the exact build of the program (format is 11.X.X.X, e.g. 11.0.7.411). 

Lastly, could you please provide the serial number of your Nitro Pro?

To send them via private message, hover your mouse on top of my name 'AllainU' and select 'Message'.

Thank you very much in advance and I am looking forward to hearing back from you. 

[Unnur Jónsdóttir]

[Allain Umailin]

Thank you @Unnur Jónsdóttir.

Please activate your Nitro Pro 13 using the new serial number I sent you privately.

Thank you for choosing Nitro and I hope this helps.

[Allain Umailin]

Hello @Unnur Jónsdóttir,

Thank you for the screenshots.

To address this rare behavior where Nitro Pro is not generating the activation certificate, please perform these steps:

1. 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/ 

2. Download and run our Clean Up utility to uninstall your Nitro Pro: 

http://install.nitropdf.com/professional_13353685/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 

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 13.35 using below offline installers:

x32 http://install.nitropdf.com/professional_13353685/en/retail/nitro_pro13_ba_x86.msi
x64 http://install.nitropdf.com/professional_13353685/en/retail/nitro_pro13_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 

5. After installation, you can activate by opening Nitro Pro, clicking on the Help tab > About Nitro Pro > Activate by entering your Nitro Pro 13 serial number

Thank you for choosing Nitro and I hope this helps.

[Unnur Jónsdóttir]

Thank you, it finally worked!