# "An unknown error has occurred while reading the video file. Connecting to Dynamic Link server faile



## glospete (May 12, 2017)

I know that this has been covered in an earlier thread but I didn't see a definitive answer/solution. I have been importing photos and videos into my library on my iMac (Sierra) but yesterday Lightroom displayed a message and listed all my video files that it was unable to import. The photos imported fine but it did not allow me to import any MP4 videos from a Sony digital camera. 

The message said:

"An unknown error has occurred while reading the video file. Connecting to Dynamic Link server failed.
Connecting to Dynamic Link Server Failed"

I Googled it but there were all sorts of explanations ranging from problems with Apple Quicktime to suggestions to reinstall the whole OS. However I kept digging and eventually found a suggestion that solved my problem and I wanted to share it with you. 

Go to Lightroom, Preferences, File Handling and at the bottom of the page is Video Cache Settings. If you Purge the Cache it solved my problem completely. But note that it can take some hours to purge the cache.


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## Victoria Bampton (May 12, 2017)

Thanks for sharing glospete, and welcome to the forum!


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## hll (Oct 22, 2017)

Thanks a lot. I am having the issue right now. I clicked on Purge Cache, but nothing seems to happen. Does it show any process happening? Or should I wait for a couple hours and try again? Meanwhile, I'm open to any alternative solutions. I use mac 10.12.6 and Lightroom CC classic.


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## glospete (Oct 22, 2017)

Are you sure you're purging the Video Cache Settings, not the Camera Raw Cache Settings? When I click on it I get the message below.


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## hll (Oct 22, 2017)

Ohhh thanks.. They moved it under the Performance and I had to click on limit video cache size to make the purge cache option to appear. Waiting impatiently for it to purge cache. I'll let you know.


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## hll (Oct 23, 2017)

It is still showing the same message, still trying to delete video cache. It seems like (according to Activity Monitor) LR does not perform anything. I found the cache files under Library>Cache>Adobe>Lightroom>Video>Media Cache Files... It is approx. 142 GB.* Should I delete them manually? There are cfa, ims and pek files. *


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## glospete (Oct 23, 2017)

Sorry I really can't advise as it worked for me using the Purge Cache instruction. I did clear my video cache files again and it removed all the files under Media Cache Files and Media Cache so it MIGHT be OK to delete manually. But I'm not advising it!


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## Hal P Anderson (Oct 23, 2017)

Instead of deleting, rename. Then if things work, go ahead and delete.


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## hll (Oct 24, 2017)

Thank you everyone! Renaming was genius! 
*I manually deleted cache files under the two folders I mentioned before/above.* LR works perfectly and it is so great to get rid of hidden 150 gb!!! So happy, thank you everyone,  @glospete, you're the hero...


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## SandyJoy (Jan 22, 2018)

Hello I tried this method and it didn't help. I tried it twice.  I even called adobe support and they could help me. Is there anything else I can do? I can upload them to my iPhoto's but LR will not let me move them over into LR


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