I’m experiencing a strange bug since updating to HIgh Sierra. Dragging and dropping an item to DTPO dock icon cause the capture dialog to appear, but it is frozen. I cannot click on any of the buttons to capture the item. The dialog cannot be closed either, unless DTPO is quit.
I’m on DEVONthink Pro Office 2.9.15, macOS 10.13, MacBook Pro 15" mid-2017 with Touch Bar.
No issues like the OP reported – and I drag things to the Dock icon frequently. My Import Preferences is Destination > Select Group, which causes the Groups and Tags dialog to open for selecting the group. Nothing freezes.
There were some reports of issues with some people using Macs with a Touchbar. This should be fixed in the next maintenance release (if you’re experiencing it).
When DEVONthink is stalled, please launch the Activity Monitor.app (see /Applications/Utilities), select DEVONthink in the list of processes, press Command-Option-S and send us the sample when you start a Support Ticket.