Invalid property '<property>' for folder '<folder>'
The Property property for the specified folder is improperly formatted. The Property property may contain ASCII characters A-Z, numerals, underscores, and periods; but it cannot begin with a numeral or a period. All letters must be uppercase and spaces are not allowed.
To correct this error
Double-click the error in the Task List to go to the specified folder in the File System Editor.
In the Properties window, select the Property property, and enter a properly formatted value.