In the transactions window, the History panel on the right-hand side only displays "Loading..." for Summary, Recent Transactions, and Notes. The information is never displayed.
This occurs most often with systems using a wireless keyboard and/or wireless mouse.
The History panel will display "Loading..." as long as the computer detects activity coming from the mouse or the keyboard. The wireless mouse or keyboard may be constantly sending signals to the computer that QuickBooks interprets as movement.
To fix this issue, turn off the wireless mouse and keyboard and use a wired mouse and/or keyboard.