This article explains how to troubleshoot issue when scanning Order unable/failed to open Quick Despatch screen.
Detail Steps
Ensure Scanning Mode is ON (Ctrl Shift B)
Option 1:
Check WMS > Tools > Preferences > Barcodes tab "Use Special barcode Terminator as (F12)" Untick this option to allow scanning to be done from RDP session
Option 2:
Use shortcut "Ctrl + 6" and manually type in Quick