"Lightroom encountered an error when reading from its preview cache and needs to quit. Lightroom will attempt to fix this problem the next time it launches".
You need to delete the Preview Cache for your Lightroom catalog.
It is located in the same folder as the Lightroom Catalog. The preview cache name ends with Previews.LRDATA and should be deleted. Do not confuse this with *.LRCAT, which should not be deleted.Below is the image of what it is named as Default LightroomcatalogPreviews.Lrdata.
Location /Pictures/Lightroom on Mac.
Delete this Folder and restart Lightroom
: "Lightroom was unable to back up the catalogue named
This means you do not have enough permissions to save to the Backup location
Select the drive to which you are backing up catalogs
Go to File>Get info in Finder
check the Sharing and Permissions section near the bottom
You must have Read and Write Permissions for that location(specially the username with which you are currently logged in )
Let us know if that helps
I'm having a similar problem, since the update of Lightroom CC.
"Similar" is not that helpful to us.
What exact problem(s) are you having?
Mac or Windows? What exact version?
What exact version of Lightroom (see the about dialog for x.y.z number)?
What possible solutions have you already tried?
Thank you for assistance, unfortunately it didn't help a lot. I deleted Previews.LRDATA files as you advised me (I'm not sure I had to delete smart previews.lrdata files so i left smart previews.lrdata), however Lightroom still doesn't work properly. The following things have been happening.
As I open Lightroom it shows me a notification: "The last time Lightroom ran, it shut down prematurely due to a problem reading the catalog. Lightroom must now check the catalog before processing". I click OK.
Then it shows me: "Now checking the integrity of Lightroom Catalog. the applications opened, i start importing photos".
After this I see the following notification: "Lightroom encountered an error when reading a catalog file and needs to quit. Lightroom will attempt to diagnose the problem the next time it launches".
I click OK and before quit it warns me about two tasks in progress: "Building smart previews" and "building search index".
I click Quit and it continues the import then, however it freezes and the import cant be finalised properly that means I can see the images in my catalog, but I still am having "Building smart previews" and "building search index" in their endless progress.
For successful backup I checked the Read and Write Permissions section, I can't find the user name options there. However as I start my computer the same name is being used both for my Mac and Lightroom log in. I used to back up my catalog without any problems before, I don't have any ideas what's been happening now. I still can't back it up.
I'm using Mac OS X El Capitan version 10.11.1 and Lightroom CC as I mentioned in my first post.
Thanks for the update and your Detailed Answer.
I checked the Read and Write Permissions section, I can't find the user name options there.
Lightroom encountered an error when reading a catalog file and needs to quit
The above messages you mentioned indicates the catalog might be corrupt
Create a new catalog from File>>New catalog
Then do File>>Import from another catalog in Lightroom and point backup catalog as source to import.
Also change your catalog backup location to Desktop
Then check if you have similar issues or not
Let us know if that helps
Thanks for your assistance. Following your advise I created new catalog, but I wasn't able to import the data from my previous catalog as the following occurred: "Can not import from this catalog at this time. Unexpected error when creating temporary working copy of the catalog".
Hello again. I tried to do the same again, just to make sure it ready doesn't work. And this time this message occurred: Can not import from this catalog at this time. The catalog is either in use by another copy of Lightroom or was closed improperly. If it was closed improperly, please consider doing an integrity check when opening.
Have you done a site search for any of these error messages, Marina? They've come up before...
Sure thing I tried, however I didn't find similar cases to employ. If you came across any can you please mail me a link?
I've been searching around the Internet for a solution and found this advisory from Adobe that directs users to uninstall the newest version of Lightroom until they get things sorted out in their engineering department: https://helpx.adobe.com/lightroom/kb/roll-back-to-prior-update.html
I hope that Adobe gets this sorted out. It's never good to be a paying customer for a product that doesn't work.
Thanks Roland, it is exactly what I'm doing now. I believe Adobe team will sort this out soon. I agree it's quite annoying when the tool you're paying for doesn't work properly and gets your workflow stuck.
Lightroom 6.3/CC 2015.3 is now available -- try updating to that version which includes the previous import functionality, bug fixes, and new camera/lens profile support: Lightroom CC 2015.3 / 6.3 now available