HP InstantInk Error UNK099

[HansWurst12390]

Yesterday, I spent several hours with HP support chat to get to the bottom of the "UNK099" error that I encounter when I try to register my OfficeJet Pro 9012e for InstantInk. The error pops up both within the macOS app and the iOS app and did not disappear after restoring factory settings of the printer and re-registering the printer. Apparently, HP support ran out of ideas and the agent just left the chat. Does anyone here have an idea on how to solve the issue?

[Kuroi_Kenshi]

Hi @HansWurst12390,

Welcome to the HP Support Community! 

We're here to help you tackle that malfunction! Don't worry, we've got your back! 

To get you the best assistance, we need to take this conversation to a private chat. We're inviting you to a private message to protect your privacy and ensure that any sensitive information remains confidential. 

To access your private message, just click the little blue envelope icon on the upper right corner of your HP Community profile, next to your profile name. Alternatively, you can click on this link. 

You can use this link as well: 

Private Messages - HP Support Community

We're looking forward to helping you resolve this issue! 

Stay tuned, and thanks for your patience! 

Best regards,

[HansWurst12390]

In the mean time, I spent another few hours with HP Support to learn that Instant Ink apparently cannot be activated when the currently installed ink cartridges are empty. So, it seems like I need to buy new cartridges first, in order to activate InstantInk, which of course would be stupid to do, as I then had new and fully filled cartridges.