Designer Planner - Not saving changes error: "Output file already in use error"

Designer Planner - Not saving changes error: "Output file already in use error"

Problem: Not saving changes error: "Output file already in use error
Resolution:
  1. Close Planner on all PCs                                                               
  2. Restart all PCs
NOTE: If anyone comes across this error message "Output file already in use error", please take a screenshot and email to helpdesk@sharps.co.uk.