Your Catalog must be stored locally on Computer/External drive.
We do not recommend saving catalog on Cloud based services.See LR5 Cat in Dropbox - Issues
Is there a way of closing LR without saving?
Lightroom always save changes when it Exits.
The catalog is a database file. It gets written to many times during your edits. Chances are that the writes happened long before you tried to exit.
Dropbox and the like are decent ways to sync your files between multiple computers. However, the less error prone way to use these services is to copy the catalog out of the sync directory to somewhere else before using it, then copying the catalog back to the sync directory after you are done with it.
Right, got it. Mmm - not too keen on copying and pasting manually. It's a lot of hassle and I'm bound to get in a mess. Still trying to perfect a multiple-computer solution... Thanks for replying!
Yes, I took a look at some of these discussions a while back before deciding to use Dropbox. I think the drawbacks to the solution are with Dropbox, not with Lightroom. Sometimes Dropbox takes time to sync so a catalog may not be "ready" to use on a different computer. Technically it's not really a "cloud" solution because the way Dropbox works is it makes copies on local hard drives. There is also a copy in the cloud, but each time you open a catalog on Dropbox it's from a hard drive. I think it's a very common thing for photographers to want to have - because lots of them travel and have two or more computers. I'm surprised Adobe haven't come up with a solution using their cloud. Thanks for replying to my question though! Richard
The easiest (not prettiest) is to put the catalog and images on an external drive and move the drive from computer to computer as needed.