Can you send us your mzXML file and your Skyline document? We will figure out what is going wrong.
In Skyline you can use the menu item:
File > Share
to create a .zip file containing your Skyline document and supporting files including whatever chromatograms have been extracted.
If that .zip file and your .mzXML file are less than 50MB you can attach them to this support request. You can upload larger files here:
"Chromatogram information unavailable" often means that there were not MS2 spectra whose isolation window matched the precursors in your Skyline document. This might have something to do with the settings at "Settings > Transition Settings > Full Scan", or it might have something to do with the mzXML file. We will probably be able to give you more information after we see your files.