In Win Explorer - and while Lr is closed - navigate to the folder where your catalog resides on the external drive and check if the lock-file is present.
The purpose of the lock file is to prevent that a catalog file can be opened twice at the same time.
Therefore it should be present when a catalog has been opened with/by Lr. But the lock-file should be deleted (automatically) and thus not be present when the catalog has been closed. It happens sometimes that on closing of a catalog, the lock-file is not deleted. It then prevents any further opening of this catalog and Lr sends the message you are getting.
With Lr closed check in Mac Finder / Win Explorer if you can find a lock-file. The lock file sits directly besides (i.e. in the same folder) the catalog file in question.
The catalog is a file with the extension < .lrcat>; the lock-file has the extension < .lrcat.lock>
If - for instance - you have a catalog file named <123xyz.lrcat>, the lock-file would have the name <123xyz.lrcat.lock>.
If, while Lr is closed, you see any such lock-file, delete it, i.e send it to the Recycle Bin / Trash Can.
Then double-click the catalog file to open Lr with it.
If you want Lr on the PC and on your laptop to be always in the same state, they both have to use one-and-the-same catalog. That means that the catalog on the external drive should be your "working" catalog. Th ecatalog backup should then preferably be on a different drive.
Thumbnails that are grayed-out are a sign that your monitor works with a corrupt (out-of-date) profile.
If you have the calibration hardware and software, re-calibrate your monitor.
If you don't have that yet, you can - as a temporary remedy - set your monitor to sRGB.
See here on how to do this:
No, no screen shot visible.
You have to save your screen shot as a JPG. Then click on the small camera icon in your reply on this forum.
Then navigate to your JPG, select it and post it.
PS. You can't do this from your e-mail program. You have to log on to this forum and click on <Reply>.
Message was edited by: web-weaver - PS Added
I'm assuming that Win 8 is not different from Win 7 in this aspect, so:
On your desktop click on the <Start> button, select <All Programs>, navigate and open the <Accessories> folder. In this folder you'll find a Program called <Snipping Tool>.
Use that to make your screen shot. First open Lr to the Grid View where you see the grayed out photos. Then start the <Snipping Tool>.
When you start the <Snipping Tool> your screen will go light grey, and your cursor will be like a cross. Then just drag a square around that part of the Lr window that you want to show in the screen shot. When you are done, still in the Snipping Tool, go >File >Save as. Save it wherever you want but where you'll find it again.
OK. Your images are not only grayed-out, they are also missing a sthe question mark on the frames (top right) and the question mark in front of the folder names indicate.
You had your images on the C drive and you must have moved them somewhere else with Win Explorer. Now the link that Lr established with the image files is broken. You have to re-establish the link.
See here on how to do this:
Let me add this...
You are correct. The original catalog is on my PC "C" drive. I backed it up to the External drive.
I then connected the external drive to my laptop. Started LR on laptop and tried to open the catalog on the external drive. This is where my problem started etc.
Will the link you show below show me how to open the catalog from the external drive?
I want to open images that I had "developed" on the PC, on the laptop. I don't want to "re-develop" them again.
Hope this is clearer.
Sent from my iPad
One question: What do you mean by "catalog"?
Do you mean your library / collection of images? Or, do you mean "catalog" in the sense of the Lr database.
With Lr, when the word "catalog" is used it has a specific meaning: "catalog" is the database in which Lr stores / saves everything you do in Lr - but it does not contain your photos.
For the photos, the word "library" is often used.
In your communications with this forum, please use the word "catalog" only in the sense of database, or else you will create confusion and not get the right answer.
So, what do you mean by "catalog"?
Sorry for the confusion as I am rather new at this.
So I have imported images that I shot on a digital camera and enhanced them in the develop module.
I have also imported images that I scanned (120 format negatives) and also enhanced them in the develop module.
This was done on my PC and saved on the PC "C" drive via lightroom.
I have an external HD.
I just bought a laptop and I have installed LR on the laptop.
How do I "transfer" the catalog or library (whichever is the better word) from the PC "C" drive to the external hard drive so that I can connect the external hard drive to the laptop so I can view all the images the way that I enhanced them on the PC without having to "develop" them again on the laptop.
Hope that is clearer.
Sent from my iPad
Yes, it is clear.
To achieve this two things have to be done:
1) your photos have to be moved from the C-drive to the external drive. I take it this has happened already since your screen shot shows the images on the C-drive as "missing".
2) the catalog ( = Lr database) has to be moved from the PC to the external drive. Since both computers (PC and laptop) need to write into the same catalog in order that you can see the edits done on the PC also on the laptop (and vice versa), they both need to have access to the catalog (= database). So it has to be on the external drive.
(Just as an aside: there is also a way to accomplish this with two catalogs (= databases) and merging them later on - but I think that would confuse things at the moment. So I am not elaborating on that).
To move the catalog (= database) to the external drive: find the file with he extension < .lrcat>. By default it is in the folder <My Pictures/Lightroom> . If you can't find it, do a search for a file with < lrcat>. While Lr is closed move this file with Win Explorer to your external drive. I suggest you create a new top-level folder called <Lightroom catalog and Previews> and put the catalog file in there. You can also move the previews folder in there. The previews folder is a folder with the extension < .lrdat>, and you will see it right next to your catalog file. Moving the previews folder is not critical because Lr will create new previews "on the fly" if it doesn't find any.
Once your catalog file (= the lrcat-file) is on the external drive (and your photos are also there) double-click the catalog file and Lr will open.
Since the catalog (= database) was created while the images were still on the C-drive, the link that Lr had established between the catalog and the image files is broken, and you see the question marks on the frames of the images (in Grid View) and in front of the folder names. Your screen shot shows that. Now you have to re-link Lr with your image files (= photos).
I gave you the two links in my post # 13. Read and watch the tutorial, and you'll learn how to re-link your photos.
Just one warning: Do not re-import your photos. Re-importing creates havoc with your catalog, creates unnecessary duplicates, and you loose your edits. The import is strictly for images only that have never been imported in Lr.
So, you have your work cut out. Good luck! If you run into problems, ask.