Confused by newest upgrade

[neils37596328]

I just updated LR and now the application isn't pointing at the upgraded Catalog. I'm sure it is operator error on my end but I need a pointer. I've historically saved my images to an external drive. It seems to be working well but Lightroom isn't finding my latest import. At first, I got a message that LR could not find the external drive and the default was to save to My Pictures on the internal C drive. I thought I reset the drive to the external drive before importing but now LR doesn't see the images. I don't see anything in the Pictures folder on the internal drive either. Any guesses on what I did wrong?

[GoldingD]

1. LrC upon upgrade can occasonally upgrade the wrong catalog. Use Windows File Explorer to see if a different catalog exists. Double click on that catalog to open/upgrade.

2. In Import, that error about not finding the drive would be about the destination, look at the destination, is it correct? 

3. A Windows PC using an external hard drive for the photos. Is that hard drive permanently assigned a drive letter? Is that drive allowed to go asleep? Do not allow the drive to go asleep, LrC sometimes has issues with that.