When you select "Save Project As" in Spine, it should indeed bring up a dialog that allows you to save your project with a new name or in a different location. If this is not happening, there might be an issue with the file dialog. One potential solution is to try holding down the Shift key when you click "Save Project As," which can open an alternate file browser. Additionally, ensure that your project is in a valid state without errors, as Spine may prevent saving if there are unresolved issues in the project. If the problem persists, you might want to check the Spine log file for any error messages that could provide more insight into the issue.