Could not read preview when choosing files to import

[maxwell_grover]

I have been using Lightroom on windows 10  for more than a year without many issues but just this last week I started getting a message while trying to go through photos on my SD card that I might want to edit. Every time I preview more than 50-100 photos I start getting the message "could not read preview". If I import the photos I already have selected then go back to import more the first 50-100 photos I view will be fine again. I am working for a summer camp doing photography for them every day for the next 2 months and this is really slowing down my workflow. Currently I just select the photos until I get the error then import an add to quick collection and go back and import a few more until the error ect... Sometimes when I import after the error it also shows an exclamation mark at the top right on a few of the photos. This should mean the files place has moved but I am never moving its location and if I had then it should say all of the files had moved but only a few of them get the exclamation mark. All of this is slowing me down so much and I could really use some help.

All the files are DNG

My cache maximum is 64gb

I have a gtx 1050, 16 gb of ram and an I7 7th gen

[Rob_Cullen]

What is your Lightroom Version NUMBER?

trying to go through photos on my SD card that I might want to edit.

This is the 'wrong' workflow IMO.  You should be importing ALL files from the camera card to the computer Hard-drive and use Lightroom to cull or select for editing.

I start getting the message "could not read preview".

This error message commonly means that Lightroom cannot WRITE the files to the set dsestination. The destination folder for the import must have available space and full Read/Write permissions.

add to quick collection

No need for this step. If you import correctly the photos will be in a FOLDER on the hard-drive referenced by Lightroom.

it also shows an exclamation mark at the top right on a few of the photos

Well this means that Lightroom has lost the location of the files.

photos on my SD card

This is possibly the root of ALL your troubles. If your version of Lightroom is allowing you to Import the photos by using the "ADD" option then the photos are NOT being imported to a folder on your HD, but instead remaining on the SD card only. If you remove the SD card from the computer all the files are now "Missing" with the exclamation mark. VERY DANGEROUS as a format of the card in camera will delete ALL photos!.

Also if you use the "Copy" option and have set the Destination as the SD card (in error) the "Could not Read/write" errors are being caused by limited space on the SD card. (The Import is trying to write to the SD card)

[maxwell_grover]

Thanks for all hat information and i dont disagree with it isnt really true for my case. i am using he latest update for lightroom, i dont transfer all the files from the sd card because I take more than 30GB of photos a day and tranfering that would be a waste of soace and time. Its not ”The wrong workflow” its just how I do it and have dine it for as long as i can remeber withiut any problems. your main idea it what is wrong isnt the case at all. Nojing is saving to my SD card. I know how to use lightroom, everythin is savjng to my hard drive via d drive. I format my card every simgle day and it doesnt deletete my catalogs. Ive created a folder in d drive for my catalogs and they are all synced properlly. Like I said, I have been working wuth lightroom for a long time and his has only just came up and not beacause of the reasons given.

[Rob_Cullen]

(My slow reply- I have been off-line)

Can you post a screen-clip of the exact error message?

There are several reasons that the error message "could not read..." happens-

Full Read/Write permissions missing of folders, limited hard-disk space, bad sectors on the hard-drive, a failing hard-drive, etc.

A few other forum threads have reported a problem (a bug?) in the Import dialog when selecting a "Device" (eg. SD card) will not show previews to import, but selecting a "Folder on the SD card"  will show the photos. Have you tried expanding the SD card folder tree in the import dialog?

[Bob Somrak]

Lightroom has had various random import PREVIEW issues in the import module from at least Version 2 (my first version). It seems to be  better than it was but I still get these "could not read preview" errors once in awhile.  If I close the import dialog and then reopen it the photos that had the issue will magically appear.  ALL, and I mean all,  the other programs I have used have no problem with loading hundreds of previews so it can't be that hard but Adobe can't or will not make the effort to clean up the code to make it work consistently.    If you are culling 30GB of photos every day you should get Photo Mechanic to do this as it is apparently fast and WORKS!  I don't use it but a couple of friends that do a lot of "spray and pray" shooting do and pre-cull with Photo Mechanic.

[Tony_See]

Hi Maxwell

Some of Lightroom's strengths are its cataloguing and metadata abilities, and I would suggest from reading your post carefully that you might not be giving LR a 100% shot at that ability.

I'd second Bob's post above though in your case, and then import ALL the remainder from the SD card to a substantial hard drive with plenty of space.