Since you are a subscribed user for the Creative Cloud, you can download the Lightroom 2015.7 version(latest) on your machine.
Open Lightroom 2015.7 with the old catalog you was using with Lightroom 5, where you have all your work. Lightroom will upgrade your catalog, so it can be used with the latest version of Lightroom.
Once its done, then you can find the missing folder and update there location in Lightroom, refer: How to find missing photos in Photoshop Lightroom
Let us know if that helps.
Mohit - thank you.
I download Lightroom 2015.7 then opened the old catalog: Lightroom 5 Catalog 3, and updated it. For the second time.
Now I have Lightroom 5 Catalog 3-2 and Lightroom 5 Catalog 3-3.
Unfortunately, the same "missing" folders which can be found on the external drive are not showing up under the Folders list?
I checked the link you sent regarding "how to find missing photos" but it seems to be addressing a different issue, one where the image has the question mark over it.
My problem is that the folders don't even appear in LR.
Any additional thoughts/suggestions would be greatly appreciated.
As said above by Geoffthekiwi you need to look for the backup catalogs and open the most recent catalog you have backedup in Lightroom CC 2015.7.
Also, if you still have the Lightroom 5 installed on your machine you can open it and then open the recent catalog as shown in above in the screen shot, It will help you to find the original catalog and its location so that you can upgrade that specific catalog in Lightroom CC 2015.7.
Hi Geoff - thanks for your reply
The screenshot below shows what's been opened recently. I always operated out of Lightroom 5 Catalog 3, but after I installed the new hard drive, with Sierra OS, LR wouldn't let me open Lightroom 5 Catalog 3 - had to be updated, which created Lightroom 5 Catalog 3-2, which is missing the folders.
Again, the folders, with the images inside, can be seen accessed on the external hard drive. I'm hoping there's a way to access them through LR while maintaining all my work.
Would importing them one by one cause problems?
The very first sentence from Geoff is
Do/Did you have back ups????
I don't see an answer. Do you?
Your screen capture indicates that the desired catalog file Lightroom 5 Catalog 3.lrcat is not in the File->Open Recent list.
You have to find this exact file name using your operating system, and then when you know where it is, in Lightroom you use File->Open Catalog and select this catalog.
Thanks again for offering to help - I tried opening every catalog I have and each time LR asking me to either update older catalog version and relaunch LR or use new update catalog - Ima lost.....
Any other thoughts?
Okay so the Lightroom 5 Catalog 3 file is there.
I suggest locating on the disk and making a copy (copy preview file as well).
Next rename to copies with identical names such as "Steve Lightroom Catalog.lrcat" and "Steve Lightroom Catalog Previews.lrdata"
The double click the catalog file to open it. Again a copy will be made and updated.
Check what is in there..... if all is well that is ok.
If everything is not in this catalog... it maybe that you were working from a backup possibly.....
THANK YOU everyone for your time, thoughts, and effort.
Thankfully, all the files were in their folders on the external hard drive. I had to manually add all of my folders back into LR. Thankfully, all of my edits have been saved.
I have back up on a second external hard drive and now in the process of backing up to cloud service BackBlaze.
Does anyone have any thoughts on BackBlaze vs. CrashPlan? Or any preferred service?
THANKS again !