Try once delete the project.json file and open again main xaml.
it not working…
reinstall windows 
I am having this same issue. The only difference between a working and non-working project file is the name, description, and uniqueID, so I am wondering if it’s something about the uniqueID is not agreeing with licensing. Any advice from UiPath?
Here is the clear answer that worked for me: In project.json, remove individual packages under dependencies (with a focus on those that may have a new version) and try to relaunch. Repeat until the project launches. Reason: most likely, I am having issues reaching one of the package repos for a recently updated package version.
I did this and the project opens up. But now i get this error when i try to add the dependencies in the project.