Recently I am having issues with placed Illustrator files in Photoshop. When I go to edit them (double-click) I get an error message: "To edit this item, please install Illustrator on your computer. If you were trying to place the item, you can do so by dragging it into an open document." I have Illustrator installed and have never had an issue with it opening placed files.
Make sure AI is the default application on you system the vector files in File explorer of finder try to open a svg or ai file does AI start up. If you uninstall a version of Photoshop or AI Adobe may have reset file extension associations.
They do not open in AI on my maching for I doe not install AI they open in other applications like SVG will be display by Chrome or open in Notpad++ or InkScape. Depends on what .SVG is asspcoiated with.