Hello, tried to activate nitro but getting -24 error. Also tried deactivate old one had same error.

[Marcin Ciborowski]

Hello, tried to activate nitro but getting -24 error. Also tried deactivate old one had same error.

[Allain Umailin]

Hello @Marcin Ciborowski,

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

We want to make you aware of the change to your product that may affect its activation performance and to further assist you, could you please provide the serial number of your Nitro Pro?

This matters because our business installers are different from the online ones.

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

[Allain Umailin]

Hello @Marcin Ciborowski,

Thank you for the private message.

We want to make you aware of the change to your product that may affect its activation performance (e.g. -2: Error - Bad parameter or -24 Error: Activation Error or -79: Activation Error) and to continue offering our customers the very best PDF tools, please install Nitro Pro 12.16.9.574 using the below offline English MSI 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 

After installation, you can activate it by opening Nitro Pro, clicking on the Help tab > About Nitro Pro > Activate by entering the same serial number 234601-xxyyzz-513457

Thank you for choosing Nitro and I hope this helps.