I can't think of any reason that Skyline would behave like that, but if you send us your files we might be able to figure something out.
In Skyline you can use the menu item:
File > Share
to create a .zip file containing your Skyline document and supporting files including extracted chromatograms.
You should send us that .zip file as well as the raw file that you were trying to import results from.
Files which are less than 50MB can be attached to this support request. You can upload larger files here:
It might also be helpful if you could post a screenshot of what Skyline looks like when Skyline seems to be stuck.