change unit encoding

I'm new to TestComplete & have inherited a test suite which was created & shortly afterwards fell into disuse.  The problem I have is that the version control system won't allow me to import as ascii, only as binary.  I've seen these instructions which tell me how to change the units encoding...

http://support.smartbear.com/viewarticle/8855/

...but when I navigate to Project Explorer/Properties/General, I only have a "Log Location" option.  To be honest, I don't have any other options at the "General Options" level.

I wondered whether or not I had a corrupted test project file somewhere & this caused this behaviour.  So I created a new project, and checked the Project Explorer/Properties/General ... it's the same in a newly created project.

I'm using version 10.60.3387.7, which I downloaded recently.