Folders located on external drive not showing up in Lightroom

[CheFigatta]

Hello,
In need help with Lightroom seeing my external drive.  I have folders on my internal drive and an external drive.  I keep only stuff less than a year old localy, then it gets moved to the external drive.

Because of this, I don't always have the external drive connected.  Usually I'll see the "?" next to those external folders.  Recently, those folders went away. Not sure when it was, but now I don't see those external folders at all, and connecting my external drive didn't do the trick.  How do I get Lightroom to recognize my external drive/folders?

Lightroom realizes there are missing photos, as it show over 90k photos missing. If it matters, I am using Windows OS.

Thanks

[JohanElzenga]

If those folders are not shown in Lightroom at all, so also not with a question mark, then you must have removed them from the catalog somehow. Do you have a catalog backup from before this happened? 

[dj_paige]

It would help if you could show us a screen capture of what you see in LrC and another screen capture of what you see in your operating system. Use the "Insert Photos" icon to include your screen capture in your reply; do not attach files.

When you say it shows there are 90k missing photos, where do you see that? Show us a screen capture of that as well.

It would also help if you could tell us the version NUMBER of your Lightroom Classic.

[CheFigatta · Accepted solution]

Thanks everyone for the responses. I figured out what was going on. I read an answer to a similar problem, and that gave me a clue as to my problem. Someone mentioned how LR is not a folder browser.  My external drive that LR was looking for was on the D: drive.  But because I had another external drive plugged in, that drive was D:, and the drive that had my photos was designated as E: drive. I unplugged both drives, then plugged the drive my photos were on. It was still being designated as E:, so I re-asigned it as D: on the Computer Management tool.  I relaunched LR and it found everything. Whew! Thanks again!

[Ian Lyons]

I'm marking above as the correct answer as it may help others with a similar issue in the future.