iTunes download error -8288
I am running iTunes 12.6.5 on High Sierra as I want to control what updates go to my i-devices. Today for the first time, I'm getting error -8288 on all i-app downloads. The download seems to complete, but when the download finishes, this error appears. BTW, an iOS system update thru iTunes worked just fine.
What I have done: Restarted iTunes; Logged out of my account and logged in again.
Any help will be greatly appreciated.