iTunes downloads: files are corrupted?

1. Open your default browser and clear its cache.
2. In iTunes use Edit > Preferences > Advanced > Reset Cache.
3. From the same dialog note the location of your media folder. Open this folder and delete the Downloads folder that may be inside it.
4. Delete the recent purchases that you think are affected.
5. Avoid hiding from your purchase history if you can, otherwise see Hide and unhide iTunes Store, App Store, or iBooks Store purchases - Apple Support.
6. See Redownload music, movies, TV shows, apps, and books from the iTunes Store, iBooks Store, and App Store - Apple Support to redownload.
7. Pick one item to download.
8. Click the activity icon at the top right while the download is in progress and make sure Simultaneous Downloads is not ticked.
9. Select and download the rest of the content.

tt2

Which build of iTunes are you running? A number of users seem to have issues with 12.6.1.25, and others had problems with 12.6.0.98/100. You might want to roll back to 12.5.5.5. See the iTunes installers section of my user tip Troubleshooting issues with iTunes for Windows updates.

tt2

You're welcome. 🙂

tt2

Then I'd try rolling back to the last build you know worked correctly for you.

tt2