Frage: blank app store/mails
After installing macOS high sierra, the app store on my MacBook Air is not working/loading anymore (blank window). And there is a similar problem with the Mail software: there is no preview and as soon as I open a e-mail there is no text at all. Can somebody help?
(and yes: i tried to quit/restart etc. etc.)
MacBook Air (13-inch, Early 2015), macOS High Sierra (10.13.2)