Quick Edit Mode in SharePoint 2013 and “Unable to communicate with server” Error – I love the Quick Edit mode in SharePoint, it really expands the functionality and makes it so much closer than Excel. However it looks like to functionality has been watered down and limited a bit more in 2013 and 2016 versions…not often we can say 2010 ROCKS.
When you need to do a bulk update via copy and paste in 2013+ you might find this issue. I use a lot to kick of a BULK workflow or fix.
Make sure the view that you are using does not show items in batches MORE than 100 (I just 99). That should resolve the issue and allow you to bulk update via copy and paste