Lightroom 'Edit in Photoshop' not working.

Responding to myself here in case anyone else has the same question - I suspect that the issue has to do with Adobe's cloud servers. I went into Lightroom > Edit >  Preferences > Cache and checked 'Store a copy of all originals',  and when I look in album view at a photo with a green check mark underneath it (indicating 'Synched and Available Offline) and try to open one of these in Photoshop, it works right away. Any photo without the green check would have to download the original from the cloud fails as described in my post above. As far as I can tell Adobe cloud is not working well today and instead of Lightroom giving a 'request to server failed' style message it just gives you a generic error message. I checked the 'Store a copy of all originals' checkbox, I'll likely have to wait hours for it to pull these files from the cloud (despite them existing already in folders from which they were uploaded on my harddrive) but after that I should have free access to them. Hope that helps anyone else that is having this issue.