TestExecute shows this message when you open a project or project suite that was created in an earlier version of TestComplete.
The project and project suite files created in earlier TestComplete versions have another format. When TestExecute opens a legacy project or a project suite, it suggests converting it to the format adopted in the current version.
The conversion makes the project or project suite incompatible with earlier versions of the product. After you open a legacy project or project suite in TestExecute, you will be unable to open it in earlier versions of TestComplete or TestExecute. We recommend that you create a backup of your project or project suite before you migrate it to the current product version.
For more information, see Migrating Projects Created in Earlier Versions to TestComplete 15 in the TestComplete documentation.