Catalogue missing last years of images

[Ute26745070qu0x]

After last update my catalogue is not complete any more, pics of 12 months are missing!

[Photovit]

Is it Possible that when you were prompted to upgrade the current catalog, you chose another one from your Catalog Backup folder?

[JohanElzenga]

Sounds indeed like you upgraded an old catalog. Maybe not from a backup, because backups are zipped so you can't select a backup copy by mistake, but perhaps the old catalog from Lightroom Classic 10 that was still in your catalog folder.

[GoldingD]

This appears to happen on many if not all upgrades, not the updates, but the upgrades. Users find their "upgraded" catalog is missing images, missing edits, missing folders, or even completely empty (as if new). In the last few days (day?) you will find several similar postings.

I suspect what happens if your preference file is corrupt in just the wrong way, LrC has issues upon upgrade opening the correct catalog, or even any catalog. 

I assume you started LrC by clicking on the start icon, the shortcut, and LrC started, then tried to open the most previous catalog (default setting), and it went downhill from their. This would be the norm (start method, that is)

If you still have v12 installed, instead of launching LrC via the shortcut, use your OS file manager and bring up the correct catalog, the v11 catalog, double click on it, see what occurs.

You might need to reset/refresh that preference file.

[Rikk Flohr: Photography]

The mode of failure is actually a combination of factors - both of which need to be true:

1.  Catalog is stored in a non-default location and
2.  The preference file has a corruption. 

If both of these occur it is possible for Lightrom Classic to lose the location of the most current catalog. In that event it is necessary to select the correct catalog to continue without an issue.