Try this.
1) Move your .cej file somewhere else (outside of the ce.lib folder and outside the CityEngine workspace) on your computer. This will be temporary as we will delete this later. In general, don't store anything in ce.lib since this is a library that CityEngine uses internally and is by default hidden from users.
2) In CityEngine, make a new project.
3) From the Windows Explorer window, drag and drop your .cej file onto the scenes folder of your new project in the CityEngine Navigator. When asked, choose to copy it to the workspace (instead of making a link).
4) Verify that your .cej file is now on your computer in the new project you created within the CityEngine workspace. Right click on the .cej file in the scenes folder -> Show in File Manager to see where it is in the Windows Explorer window.
5) Now, you can delete the temporary copy of your .cej file that you made in step (1).
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