I have a PC with Adobe Cloud Lightroom CC and Photoshop CC apps. My catalogs are missing. My computer crashed while I was on deadline processing newspaper photos in Lightroom. I hard rebooted the computer and opened Lightroom and resumed editing. I didn't notice if the catalogs were missing because when I reopened LR it was in "develop" mode and my photos were there for continued processing. I shut LR down and later that evening downloaded and installed Microsoft Office 2016. (I have no idea if that is relevant.) The next time I opened LR the catalogs were gone. I found .lrcat files on my in Lightroom folder doing a computer search, but when I found them through LR and clicked on it, LR said file did not exist. The same happened when i tried to go to LR backup. The folder shows up in search on my C: drive but it does not even appear when I search using LR. If I uninstall and reinstall LR will that create new catalogs. If not, how can I get my catalogs back? My catalogs were by date of imports. Thanks.
Well, there is default location for Lightroom catalog until you changed to something else.
Please check the above location for the Lightroom catalog, also was you using any external drive until everything was working fine.
For creating a new catalog in Lightroom you can launch the application while holding down the shift Or Opt key and it will give you the option to create a new catalog and to see the old ones which you was using before.
The only process I know of that will delete your catalog file — and that process is that you, the human user, actually use your operating system to delete the file.
So ... what you want to do is use your operating system to search for all files whose name ends with .LRCAT and then, in your operating system, double-click on each file you find to open each file in Lightroom, and then you should be able to find the catalog with the desired photos.
You might also want to make your life much simpler in the future by using one catalog.