I want to organize the library. I went into the property of the library "Aircraft" and changed the name to "Transportation_Aircraft" Now I have both libraries. The "Aircraft" Library give a message that it is corrupted. How do I get rid of the old library. How do I change the names, so I don't have this problem.
Those libraries are COPYRIGHTED and that may be your problem. You may be able to copy it but the way it is installed may not allow a rename. You might be able to do a copy but you would still have two libraries.
You may have to re-install the software to get things back to normal.
I don't think you're intended to add to one of these existing libraries. You should create your own and keep a copy yourself - separate from the product so you can put them in place if/when you install on a new device.
I was able to cut/past the libraries to another file, then rename the files back to what they were, then copy back to the original folder. So I have fixed my problem and have a copy of the library.
Very Good! Now you can keep a "backup" copy of your libraries for use in future installs and still use PCStitch the way you want. Just be sure to repeat that process if your library continues to expand.