Re: How do files end up corrupted or lost with Clo...

Thanks for the screenshots.

Looking at the last one it's pretty clear that something is preventing the download ("Pending" status for the local file), but no indication as to what might be stopping it. Looking at the overall sync status screenshot, I notice you have a cloud storage allowance of 100GB, so would I be correct that you have a subscription that is part of a team/enterprise/educational subscription? If so, which particular type?

Following on from that, where are you running the Lightroom app from....your home of some form of business premises? I'm wondering if perhaps there's a firewall issue preventing downloading? 

I assume you've tried rebooting your system and checking your local fireewall settings?