Please go to Lightroom preferences (Win : Ctrl+,) , (Mac : Cmd+,) and then open the Lightroom mobile tab. Here you can see the pending sync activity. Do you see those images in the sync activity here ? If yes, check what is the state of that error. May be attaching a screenshot would help us.
<img title="Image https//d2r1vs3d9006apcloudfrontnet/s3_images/1620167/RackMultipart20170710-79662-1uy8h5d-image_inlinepng1499719107" src="https://d2r1vs3d9006ap.cloudfront.net/s3_images/1620167/RackMultipart20170710-79662-1uy8h5d-image_inline.png?1499719107"><br>This occurred when my hard drive crashed and I had to reload everything. Only photos from 2016 are affected by this. I get the icon on the photos "Error writing metadata" and "Error syncing with Lightroom mobile". On some photos I get the error icon "Lightroom has encountered problems reading this photo". Some of the photos I am also unable to email them. Thanks, Bryon<br>
Can you create a new collection and set it to sync, and then put all those images in "All Sync Errors" into this new synced collection ?
Also, when you say hard disk crashed, was it connected to Lightroom during that time ? Were you importing any photos or some activity happening when the issue occurred ?
