Digital Foci ext hd is not giving access to files. Windows

So, have you now attempted to use it via Windows File Explorer?

Remember, LrC Folders Panel uses the OS file management. So it is important with such problems to see if the OS file management is having issues.

And if the OS File Manager can access that device, you could then copy the images from the device to the desired folder, then in LrC Import selecting ADD as opposed to Copy.

If this device has worked well for years but is showing signs of trouble, have you run any Windows disk diagnostics on it to try and check for detected problems and maybe repair them? Or disk utility software such as CrystalDiskInfo or Spinrite?

I found a review of the Digital Foci, which is a device that you can copy memory cards to it's internal drive. When attached to a computer, it is supposed to appear to the OS (Windows) as an external drive. It wasn't clear if it can be used as a external drive or if the best practice would be to copy the image files from the Digital Foci to another drive on your computer from where they could be properly imported into Lightroom Classic.

Is that a Lightroom Classic message?

Are you able to access the drive and see the files in Windows Explorer?

Does your Lightroom Classic Library know that the files are located on D:\ from a previous external drive with the D:\ designation?