Error in preview cache

[olefoto]

Up to 2 times a day, I get this message and must start building preview again.

Every time I re-build the previews, the preview file gets bigger and bigger.

I am using newest LR and MacOS 15.3.1

[JohanElzenga]

Open your catalog folder and delete 'catalogname previews.lrdata'. Then start Lightroom Classic again. Lightroom Classic will now have to rebuild the entire previews cache, so initially you will not see any previews at all, but then they appear one by one.

[olefoto]

That solves the problem with preview-files getting bigger, but not the many errors of preview-file beeing damaged.

[JohanElzenga]

If the previews are getting damaged all the time, then perhaps this means the catalog is damaged. Do you have a backup from before this started to happen?

[olefoto]

I have backup, but that will set me back too much 

[dj_paige]

Previews getting corrupted repeatedly could be a malfunctioning hard disk. Try copying the catalog file to a different disk, open it in LrC and let it rebuild the previews there, and see if the problem goes away.