After a long break from lightoom I find my catalogue has become faulty. I may need to start again w

[sockit]

My catalogue has become degraded and there is a huge mismatch with the photos file. what should I do

[Rob_Cullen]

Sometimes the work to re-construct and re-link folders and photos in an 'old' catalog may not be worth the effort if the problem is "huge".  MISSING FILES AND FOLDERS-(Computer Darkroom) 

It could be easier to simply start a new empty catalog and Import all you photos to the new catalog. (Use the [ADD] option to leave them in their current folder location.). It means you lose all previous editing work, and collections, etc. [MENU: File > New Catalog...]

Only you can decide which way to go-  Re-construct, or start a new catalog.

[sockit]

Thanks that is very helpful though I had done a lot of face recognition is there a way of retriving that?

[Rob_Cullen]

Face Recognition is only available in the catalog, and if you start a new catalog then you begin again from 'nothing'.

Your "huge mismatch with the photos file" can only be remedied in a current catalog by re-linking those 'Missing' folders and files. (See link in previous post).  If you can re-construct the Folder & File tree exactly as the Lr-Classic folder panel shows it then you might find re-linking is easier or even not needed.

There is no easy way if you have scrambled your files on disk with the operating system.

Another link- MISSING FILES & FOLDERS (Lightroom Queen) 

Rule #1 in Lr-Classic:  NEVER 'touch', move, rename, or delete, files and folders that are indexed in a LrC Catalog..

[sockit]

Tanks once again for the help..   I was finally able to reconstitute the system by going back through the saved archives and found one which was not corrupted.  I had been developing some of my files from film negatives using lab neg pro., and thought that I had exported the developed image leaving the raw RS2 file on my system.   What I have is the RS2 file but the image is the developed image.  I don't know how to handle it. I want to keep it and further work with it. I realise that if I change it I might then display  the original RW2 format however I want to keep this transforned imag too.  How do I do that  could it be in JXL format with bigger colour gamut or would it be wiser to use jpg

thanks

[Rob_Cullen]

"What I have is the RS2 file but the image is the developed image.".  That's OK and the develop adjustments (for the RS2) only exist in the Lr-Classic catalog (or a saved XMP sidecar). The raw files are never changed.

You can re-edit the RS2 in LrC or export once again.

JPG or JXL is your choice. IIUC the major difference is the compression factor.

(Not conversant with Neg Lab Pro.)