I am working with an existing project my coworker created. I want to copy the entire project to use as a starting point of a new project. I thought I did it correctly by copying the old and renaming it as a new project. But whenever I make a change to the old project, it also updates the new...and when I update the new, it also changed the old. I must have done something wrong. Can someone please help guide me?
Could a source control application be the issue here? If you have copied the project files, you may still have the source control app mapping. Try copying the project and removing all source control mapping before adding the source back to a new location.