I recently upgraded from SketchUp 2017 to Sketchup Pro 2021. It said i needed to delete the 2017 version and when I did, it also deleted all the files associated with 2017 and i cant find them anywhere. Please HELP!!!
You shouldn’t have been told you need to remove SU2017. It isn’t a requirement to install a new version of SketchUp since each version installs separately.
As for your model files, where were you saving them? Removing the SketchUp application wouldn’t touch your model files unless you were saving them into the program files. By default on the PC the files should be getting saved into My Documents unless you changed it. Is it possible you deleted all of your SketchUp models? If so, they might still be in the Recycle bin.