Lightroom 4: Preview Cache Problem Prevents Opening

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  • Problem
  • Updated 4 years ago
  • (Edited)
LR4 will not open because it says it is having a problem reading from preview cache and has to close. How can I fix this? Windows 7, 64 bit. No problems until recently.
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Tina Manley

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  • frustrated!

Posted 8 years ago

  • 3
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Dorin Nicolaescu-Musteață, Champion

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Trash it.
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Tina Manley

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How can I trash it when I can't open the program? Thanks.
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Becky Sowada, Adobe Employee

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Official Response
Dorin means trash the preview cache. To do this:

1. Locate where your Lightroom catalog resides using Windows Explorer. By default, the Lightroom catalogs are saved in Pictures\Lightroom. The default catalog (for Lightroom 4) is called Lightroom 4 Catalog.lrcat. DO NOT delete your .lrcat file - that is your catalog, and very important.

2. In the same folder as the catalog file (.lrcat), you'll see a folder with a name ending in "....Previews.lrdata".

3. Optional - copy the "....Previews.lrdata" folder to a safe backup location. This file can be quite large so it's not a requirement as all previews can be rebuilt from the original images.

4. Delete the file with the name ending in "....Previews.lrdata"

5. Restart Lightroom.
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Natalie Strand

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Thank you, this answer was very helpful. How can I prevent this error from occurring again in the future?
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Rob Cole

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I don't think anybody knows how to prevent it in the future - usually it's a rare one-time anomaly (maybe due to a hardware mishap or some obscure bug..).

Has it happened more than once to you?
Has it happened more than once to you?
Has it happened more than once to you?
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laurent suinot

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This reply was created from a merged topic originally titled
Lightroom 4.2 fails to initialize due to read error in cache memory.
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I have done as suggested but I still get the same message (even after a restart)....any suggestions??....Using LR5
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john beardsworth

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Make sure you have deleted the previews.lrdate folder for the catalogue you are trying to use. You've probably deleted anther one.
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Bryn Forbes

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if you're unsure about this, consider rather than deleting the previews folder you can temporarily rename it, and lightroom will think it's gone and rebuild the previews. If that works then you can go ahead and delete the old renamed previews folder. Just a little safer