Steps to reproduce:

• Start tracking with two created tools in 'IGT Tracking Toolbox'
• Select tool to calibrate and calibration pointer in 'IGT Navigation Tool Calibration'
• Select manual calibration method in tab 'Tool Tip Calibration'
• Edit tool tip
• Click 'Save Calibrated Navigation Tool' button
• Choose a file name and click 'Save'

--> File was saved without extension *.IGTTool

• Add file extension manually to file name
• Restart workbench
• Create new tool storage in 'IGT Navigation Tool Manager'
• Click 'Load' and select the saved tool

--> Error: Invalid file: cannot parse tool data.