Issues after latest update

LOTS of my photos have disappeared of my hard drive.

By that do you mean they are missing or simply not shown in the catalog, or they are actually not o n the hard drive?

Typically after an upgrade or in this case a nasty update that results in a upgrade of the catalog, when photos go missing in the catalog, the cause is LrC upgraded the wrong catalog. The cause for this has not to my knowledge been documented but i assume a corrupt preference file is involved. Solution is normally to locate the correct catalog outside of LrC, and open it (double click on the file)

This problem often shows up in Discussions in this community when Upgrades occur. This time, the LrC update involved a similar upgrade of the catalog, hence this issue is showing up.

If the above gets you going again, in terms of the missing photos, but likely not your other issues. You might want to consider resetting the preference file that may have gotten corrupted. (No, I do not know if that is the case)

• https://www.lightroomqueen.com/how-do-i-reset-lightrooms-preferences/

Next up is an inquiry as follows:

Please post your System Information as Lightroom Classic (LrC) reports it. In LrC click on Help, then System Info, then Copy. Paste that information into a reply. Please present all information from first line down to and including Plug-in Info. Info after Plug-in info can be cut out as that is just so much dead space to us non-Techs and it takes up vast amounts of scroll space making the reply less readable and less likely that others will bother with your post.