"Missing" photos detected when synchronizing folder

[2fifty6]

Hello,

I've found a few threads on an issue similar to this scattered around Adobe's official LR forum, but most were old and none seemed to really go anywhere solution-wise—nor did they have as straightforward a scenario as this. I posted a version of this there, but it's all crickets so far, so I figured I'd try my luck here as well in case this rings a bell with anyone.

Here's what's going on, conveniently summarized in three easy steps:

1. I use the "Import..." button in Lightroom's Library module to import a folder called "iOS" containing subfolders with 10,886 images, using the "Add" option to keep them where they are and maintain the folder structure.
   (NOTE: In case it's relevant, the subfolder hierarchy is in the form of iOS>year>mmMonth; for example, "~/iOS/2014/02February/[photos]". No special characters anywhere in the full folder path, except for the space in "Macintosh HD," which probably doesn't count.)
2. I select the main "iOS" folder in Lightroom's Folders list and click "Synchronize Folder..."
3. Lightroom's dialog box claims there are 2342 missing photos. (See attached screenshot.)
   

Other relevant facts:

• Going to Lightroom's drop-down menu and selecting "Library>Find All Missing Photos" returns the message, "No missing photos. All photos in this catalog are available."
• After opening the "Synchronize Folder" dialog box for the "iOS" folder, clicking the "Show Missing Photos" button, right-clicking on any of the images in the resulting collection, and choosing "Show in Finder," that image is presented in its folder in Finder without a problem.
• I can view and work on those photos in LR without any problem. In other words, they certainly don't act like they're missing.
  
• Removing the main "iOS" folder from LR's catalog and then trying the import process again has the same result: 2342 photos (presumably the same 2342) that "Synchronize Folder" wants to kick out of the catalog.
  
• There are other folders scattered throughout other parts of my collection (i.e., apart from the "iOS" folder) that have similar "missing images" behavior upon synchronizing—even though their images, too, are all where they should be. The example in the steps above is just the most egregious example, since I have done literally nothing with those photos and folders except import them.
• I am running Lightroom 6.6.1 on a 27-inch Late 2012 iMac running OS X 10.9.5

Some of the similar forum threads I found are from way back in 2012, so this is clearly not a new issue. I would hope that this means it's not an unaddressed Lightroom bug (since I have faith that the developers would have noticed and fixed such "image-disappearing" behavior by now) but rather has something to do with the files themselves or the way they're brought into the catalog.

So...any thoughts? Better yet: any solutions?

 

[Johan Elzenga]

Can you make some screenshots of the folder panel showing the hierarchy of that folder? And a screenshot of some of the 'missing' images in the grid? The only thing I can think of is that your problem is related to the 'double folder' problem that comes up here regularly. That is caused by the fact that Lightroom is case-sensitive (so it thinks that a folder called 'iOS' and a folder at the same level called 'IOS' or 'ios' are two different folders), while the system is not (so the system thinks they are one and the same folder).

 

[2fifty6]

Can you make some screenshots of the folder panel showing the hierarchy of that folder? And a screenshot of some of the 'missing' images in the grid? The only thing I can think of is that your problem is related to the 'double folder' problem that comes up here regularly. That is caused by the fact that Lightroom is case-sensitive (so it thinks that a folder called 'iOS' and a folder at the same level called 'IOS' or 'ios' are two different folders), while the system is not (so the system thinks they are one and the same folder).

Ask and ye shall receive!

Here's what the relevant heirarchy looks like in Lightroom:

Here it is in Finder. Note that "iOS - unsorted" and "iOS - unsorted pngs etc" are not folders I've chosen to have in Lightroom. It wouldn't be getting confused by those somehow, would it?

Here's what the path looks like in Finder. (The unabridged version would basically look like "Macintosh HD > Users > username > Images > Camera > iOS > 2014 > 04April", where username is a single, lowercase word with no special characters or other fanciness.)

EDIT: Forgot to address the part showing some of the "missing" images in the grid.

Here's a shot of some of the photos in the strip at the bottom after clicking "Show Missing Photos." Lightroom gathers them in a temporary collection titled "Photos Missing From Folder 'iOS'." Oddly enough, today it only says there are 2340 missing photos. I haven't touched Lightroom since submitting my original post, so I'm not sure how LR somehow "found" two of those missing images in the interim.

The grid view of the collection looks very similar:

 

[Johan Elzenga]

Unfortunately, these screenshots are of little use, because they don't show any information on the images. I can't see image names, and I don't see the 'missing image' icon (exclamation mark). Please turn this on in the view - view options menu and make another screenshot of the grid. I need to see the name of the images. Also make sure they are sorted on capture date.

 

[2fifty6]

Unfortunately, these screenshots are of little use, because they don't show any information on the images. I can't see image names, and I don't see the 'missing image' icon (exclamation mark). Please turn this on in the view - view options menu and make another screenshot of the grid. I need to see the name of the images. Also make sure they are sorted on capture date.

My apologies. I guess I wasn't sure what you were looking for in the screenshots. Here's another attempt, with expanded cells in the grid section:

Here are the settings I used. I didn't see anything specifically referring to enabling/disabling a missing image icon, so I assume it's covered by one of the other options. Though I think you just hit upon my main point: Lightroom's "Synchronize Folders" tool for some reason wants to treat these like they're missing, but they're NOT missing—and everything else in the way Lightroom behaves (like not showing a "missing image" icon) seems to agree!

EDIT: A couple more screenshots. Here's the same section of photos in compact cell mode, showing the folders they're in:

And here's where Finder shows those same images (at least the ones in the folder from March):

 

[Johan Elzenga]

Thanks. I don't see anything out of the ordinary, except that you do not rename your photos on import, so there could be photos with the same names in other folders. That should not be a problem, but there are reports (about wrong previews for example) that suggest that Lightroom may have a problem with that from time to time. You could consider renaming them so they are unique (add the capture date at the beginning of the name, for example).