Are you saying the project remains greyed out (and doesnt expand) after youve attempted to import an existing project?
If "yes", then this happens if the project file has become corrupted in some way....probably malformed .xml is the typical reason ive seen this happen before.
You can fix it (ive done this myself). To fix youll need to launch the project .xml file in something that has an xml parser that shows malformed parts of xml.....like xmlspy or notepad++ (with xml parser plugin), etc., etc.
Youll then be able to see the corruption....possibly badly encoded quote marks or some substitutiom characters that you can then replace making the xml wellformed again.