Lightroom Classic - THIS FILE COULD NOT BE FOUND

You stated in a post, " 6/26 Catalog file is LOCK ".

Open the folder where your Catalog file is located, by default the folder that contains your Catalog is in a sub-folder named Lightroom and will be in your, Photos/ Mac My Photos / Win, folder. If there is a file with the same name as the Catalog and the extension .lrcat.lock (LRCAT.LOCK) delete the LOCK file.

It is a temp file that will block you from opening that Catalog file which protects the Catalog file from being used by another user.

Where do you store the images?

What drive?

It would seem that you have opened a different catalog. In your menu options, try choosing the option to open recent and see if you have the option to choose a different catalog that will display the images you have been working with. This is a user supported forum, we are all just other users like yourself who are offering suggestions  and support where we can. You  are NOT addressing Adobe or Adobe support.

Hi,

We're sorry about the trouble with Lightroom Classic. Apart from the questions Jim posted, please check if you see an exclamation mark [!] on the top right of the thumbnails. If you do, you can check out: https://helpx.adobe.com/lightroom-classic/help/locate-missing-photos.html

Let us know if it helps!

Regards,

Nikunj

Not enough information to go on. What exact version of Lightroom are you using? What operating system are you using? Are the images on an external hard drive? Details about your computer system would be helpful. A screenshot of what you see in Lightroom would also be helpful.