Export from RAW to jpeg is incomplete.

[JLBrown]

I am using Lightroom CC, always updates, current version is 5.7.1 and Camera Raw is 8.7.1.

I only shoot in RAW (Cannon CR2) anymore and use Lightroom to edit and export to JPEG for most shots. When I export roughly 10-20% of photos fail to export, I get a box that lists which ones failed. This means in turn I need to write their file numbers down, find the individuals shots and reattempt to export, and the larger the batch the more time consuming and irritating this becomes. I shoot lots of competitive sports sets based on teams, and those routinely can be in the several hundreds each team and set.

Is their a setting or export versions that addresses this, to limit or eliminate this batch export error?

[dj_paige]

When I export roughly 10-20% of photos fail to export, I get a box that lists which ones failed.

Show us a screen capture so we can see the full error message.

[JLBrown]

Here is a screen capture just now made from a batch of 24, from this morning 26MAR2017.

[JLBrown]

And yes, I can go find these same files, attempt again and most if not all are usually successfully exported.

[Just Shoot Me]

Where are you exporting them to, which folder and drive?

[JLBrown]

Child folder of the source folder, same External HDD (USB 3.0). Buffer underruns should not be an issue with USB 3.0. However I did do a test run to the C:// (SATA) drive and had zero errors with the same batch, so it could be using the External-HDD.

[dj_paige]

"Could not be written", usually indicates a permission problem or a drive connectivity problem.

Since the other files in the export work, this isn't a permissions problem, but it could be that your drive is either going to sleep or the connection with the drive is not continuous.

[Just Shoot Me]

I believe it to be a connection problem. You should go into the Advanced Power options and under USB make sure the Turn Off setting is set to Never then test. If it still fails then you might have a problem with the drive or the permissions.

Does the external drive have it own AC power adapter or is it powered by the USB port.

[JLBrown]

It is externally powered with an AC hookup. I have seen nothing to suggest lost of connection, but perhaps the bandwidth needed for read/write is not there even with USB 3.0?

[Todd Shaner]

As has already been suggested your drive is disconnecting or defective. This has nothing to do with bandwidth unless you are manually disconnecting the drive before the data transfer has completed.

What exact USB 3.0 drive model, system model, and OS version are you using?

[JLBrown]

It is a Western Digital 4TB My Book. I cannot tell of any connection issues past this one. But it must be the writing side to the HDD. Photos still stored on it, but now exporting directly to the main SATA drive with no issues.

[Todd Shaner]

You did not provide an answer to "system model, and OS version," but I'll try to help. The following instructions are for Windows systems:

1) Follow the instructions at the below link to disable Power Management:

http://support.wdc.com/knowledgebase/answer.aspx?ID=3875

2) If that doesn't resolve the issue try tuning off 'USB Selective Suspend:'

USB Selective Suspend - Turn On or Off - Windows 7 Help Forums

[ManiacJoe]

I seem to remember LR 5 having some issues when other programs were monitoring the folder that LR was trying to write to.

If you have Finder or File Explorer open on that folder, try closing it.

If you have other programs watching that folder try closing them, too.