Invalid File Name Measuring a formula

After creating a new project, and you start measuring, you get an “Invalid File Name” error whenever you save the formula.

This is due to the name of your project being too long. Do not attempt any more measurements, Close the Estimator module and create a new project with a shorter name. Watch out for illegal characters like / \* etc, and preferably no spaces

You can change the name to its required long length just before costing your project for the final time.