We are going to need more information and probably your files, Karin. You can use File > Share to create a .sky.zip file and upload it to
It sounds like you are clicking the Explore button in the Peptide Settings - Libraries tab and getting a message that the settings have changed and need to be saved when you did not expect this message?
You can also get to the spectral library explorer through View > Spectral Libraries. Does that work?
To understand why Skyline thinks you have made changes to your Peptide Settings when you do not feel you have, we'll need to file that is causing the issue. So, please upload that.