I have not been able to find out exactly why lightrooms started forgetting things, particularly distressing was her forgetting collections. I knew she was a high maintenance mistress and I had been routinely backing up her catalogue but it would seem the problem occurred in bits and pieces, just a few collections here, then a collection or two at another time. This hasn’t stopped me using lightroom but I am careful to use just a smaller catalogue of recent photos I wish to post process at the moment and no memory losses so far.
There where almost 100 backups so going back through everything looked like a nightmare. Transferring collections is possible (you have to export them as a catalogue) but it does involve exporting the images in the collection and the last thing I wanted was having to alter existing the folders and files, or generate a lot of duplicates. I had also got very used to using AfterShot Pro to write sidecar files as a way to transfer metadata and ratings. I had also worked out that the collections (or albums) could also be written into the metadata, using something like the ~alb (for album) prefix in your metadata. This are then easy enough to find or filter in your photo manager and can be used to “re-find” the desired collection (album).
So I haven’t tried to rebuild a full catalogue of all my archived photos, what I have done is progressively worked through the backup (with the catalogue running from an external backpack location and then use lightroom to write a suitable ~alb collection name tag to the photos in that collection into the metadata, creating a xmp sidecar file for the photos involved. Ok that is taking time but I think storing the collections in a way that can be shared around the software packages I use (the one that can read the metadata in xmp files) is a worthwhile step. Reloading the photos into lightroom is now just on an ad-hoc basis. It will still take me a few months of occasional work to recover all my collection organization but I can see the light at the end of the tunnel.
For new photos I really like the OnOne Perfect Photo Browser. version 9.5 now supports Albums and it is a simple task to transfer these into lightroom collections. More importantly I only load those photos in the collection into lightroom. Naturally I also make sure I add the ~alb codes into my metadata before doing this transfer.
The days of trusting lightroom to look after my entire collect are over but I am still glad to let her beautiful develop tools enhance my work.