Excel hangs choosing Use All Remaining Changes... due to shared workbook.

Cause:

Users in a shared worksheet made changes that conflict with each other. Choosing 'Use All Remaining Changes from My Session' or 'Use All Remaining Changes from the Other Session' resolves conflicts without prompting the user for each conflicting cell. Excel will take some time to update the changes if multiple changes have been made.

Solution:

Switch to another application in Windows while Excel is resolving conflicts.
NOTE: Do not press CTRL+ALT+DELETE to close the program. Excel will appear as (Not Responding) even if it is still running.