After updating HP mfc drivers when trying to access the scanner functionalities the error “Imaging device not found” was popping up. Uninstalling and reinstalling the HP driver pack was not solving the problem.

The solution is pretty simple, but find it was really time consuming at the end I found this post on HP Support Forum.
The following is a summary of the reported solution:

• Download the Microsoft MSI Cleanup Utility, and install it.
• Fully uninstall the HP software choosing the printer from “control panel” -> uninstall applications (in my case the uninstaller was also crashing during the process).
• Reboot the machine.
• Then from start menu run “Windows Install Clean Up”.
• From the utility select to remove the all bdp_scan, BDP software and HP related entries.
• Reinstall the HP software package.

Done, now you should be able to use your scanner.

Note:
This error can also appear after hibernating or suspending the computer, in that case instead of restarting it, just restart the “HP Network Devices Support” service and the device will work again.

net stop HPSLPSVC
net start HPSLPSVC