I was trying to duplicate a project using this process Duplicate and rename Xcode project & associated folders
It wasn't working for me, so I deleted the duplicate folder. I'm reasonably sure I didn't delete the original project, or change any of its files or filenames. Now when trying to open the original project, I get the error
"Xcode does not support opening folders without a project or workspace."
I don't know what triggers Xcode to recognize something as a project. Any idea what I did?
Edited to ask a more specific question: How can I open this existing project, and then do whatever needs to be done to make it usable?