It happens to all of us: you try to open a catalog in Lightroom and an error message pops up.
“The Lightroom catalog cannot be opened because another application already has it opened.”
Panic strikes! This catalog can not be open in another application …
OK … Let’s remain calm … Reboot the computer and everything will be alright … Right??
A reboot didn’t solve the problem
What’s going on?
To prevent a catalog being opened by multiple users, which could cause conflicts, Lightroom “locks” the catalog as soon as it’s being opened.
When you close the catalog, Lightroom will unlock it and there will be no problem opening it again.
But sometimes things go wrong and the lock remains.
So next time you try to open the catalog, Lightroom sees the lock and will pop up the error message.
How to solve it?
The solution is simple.
Navigate to where your catalog is.
Normally you will find a file there called “<catalogname.lrcat>“.
But when the lock is on, you will also see a file called “<catalogname>.lrcat.lock“.
The only thing you will have to do, is remove the “.lock” file (or rename it if you think deleting is too risky).
When you now try to open the catalog, you will see that everything is up and running again.
This problem is often seen in online Lightroom user groups.
People panic because an error message pops up and they don’t have a clue what to do.
But when you type the message into a search engine, like Google or Bing, the solution can easily be found.
In this case, it will take you directly to the Adobe support page: