Lightroom Classic [catalog will not open. Another app is using LrC]

[Risto V]

Hello! I have very difficult problem with my lightroom.. it does not open anymore at all. It says that some other app is using lightroom and it cannot be opened. Also it suggests that I should open or create new catalog for lightroom. I dont know what to do.. should I just remove the hole lightroom and re install it. Also when I try to updtate lightroom it says that my mac (OS Catalina) should be updated to new..

My email is <email address removed> if someone wants to help me 🙂 I would be very happy.

Thank you, Risto

[johnrellis]

See this help article:

https://helpx.adobe.com/lightroom-classic/kb/lightroom-error-catalog-cannot-be-opened-lrcat-lock.htm...

[Risto V]

Thank you! I did do as said in that, removed lock file but it did not help.
Lightroom will
still not open

[Per Berntsen]

Do you have more than one catalog?

If so, you may have deleted the lock file for a different catalog.

[Risto V]

I have many catalogs.. I just dont understand anything about them.. now I
got into lightroom but none of my images cant be opened in new catalog I
made

[Per Berntsen]

Most of us only need one catalog. Having several catalogs when only one is needed, inevitably leads to confusion and frustration.  See https://www.lightroomqueen.com/one-or-multiple-catalogs/ and https://www.lightroomqueen.com/free-downloads/

If you have managed to open LrC, go to File > Open Recent, where you should find the catalog you were last using.

You can merge all your catalogs into one by going to File > Import from another catalog, and merge all your catalogs into one.

See https://www.lightroomqueen.com/merging-catalogs-overview/

[Per Berntsen]

When LrC is running, there is a lock file present in the folder that contains the catalog.

The lock file prevents other users from accessing the catalog.

It is normally deleted when you exit the program, but if it crashes or doesn't close down properly (for instance power failure), the lock file might not get deleted, and you'll get that error message.

To fix this, you have to delete it manually.

With the Finder, go to the folder that contains your Lr catalog. (usually inside the Pictures folder)

Delete the file with the extension .lrcat.lock  Do not delete anything else.

Now launch LrC.

[Risto V]

Thank You! I did remove the lock file, but it still says the same thing, so
I did not help.
Now what can I do?

[dj_paige]

Thank You! I did remove the lock file, but it still says the same thing, soI did not help.Now what can I do?
By @Risto V

USING YOUR OPERATING SYSTEM

Find all of your catalog files on all of your local disk(s), using your operating system's search feature. These are files whose name ends with .LRCAT (might be lower case). Go to the folder that each catalog file is stored in and make sure the .LOCK file (if it exists) is deleted from each of these folders. Do not delete anything else.

Once you have fixed this, you need to get serious and combine all of your catalogs into a single catalog (unless you have very good reasons not to do so).

[AxelMatt]

Which version of lightroom do you use?

Which version of  MacOS do you use?

What's the exact error message? Please post the message word-by-word.

What has been chenaged on your system before the error occur?  

Please search after .lock files on your whole hard drive in Finder. If there are find one or more please delte them and try again. 

If this doesn't help try is to reset the preferences to the default settings.

• Reset Procedure:
• Close Lightroom.
• Windows: Hold down [Alt]+[Shift] while restarting Lightroom.
  Mac: Hold down [Opt]+[Shift] while restarting Lightroom.
• Overwrite the Preferences when prompted by the dialog.
• Close Lightroom.
• Restart Lightroom.

It's recommended to backup your preferences before you reset the preferences to the default settings: 

https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html