Hello panagiotis91,
We have a great support article that might help with this. Please take a look at it here: Resolve issues between iCloud for Windows or iTunes and third-party security software - Apple Support. Follow this guidance:
"If your security software is causing an issue with iCloud for Windows
- You can't sign in with your Apple ID.
- You see "Verification Failed: An unknown error occurred" or "An error occurred during authentication. Please try again."
- You see "Your setup couldn't start because your username or password is incorrect" or "Your setup couldn't be started because the iCloud server stopped responding."
- iCloud services won't update.
If your security software is causing an issue with iTunes
- Your iPhone, iPad, or iPod touch aren't recognized in iTunes, or they won't back up, restore, update, sync, or activate.
- You see iTunes Errors 4, 6, 1630–1641, 3000–3999, or 9000–9999*.
- You can’t connect to iTunes Store to buy or download content.
- iTunes won’t open.
*If you see error 9006, your computer might not be able to connect to Apple servers or your iPhone, iPad, or iPod touch. Check for communication issues between iTunes and Apple software update servers. If you still see the error message, then continue reading to learn how to check your connectivity and security software.
Things to check first
Before you change your security software's setup:
Test your connectivity
- Check your hosts file to make sure that it's not blocking iTunes from communicating with Apple's servers.
- If you’re having issues using AirPlay, Home Sharing, iTunes, or Remote, test the connectivity between the computers or devices in your house. They should be connected to the same network and subnet in order to function properly.
Test your security software
If you still have trouble after you test your connectivity, your security software could be interfering with your computer's connection with iCloud for Windows or iTunes.
In some cases, it might be necessary to temporarily remove your security software to isolate an issue. Some Internet security apps don’t uninstall completely, so you might need to download and run a cleanup utility for your security software for it to be completely removed.
Work with your security software provider to allow the complete list of ports and services that Apple products use or if you need help with uninstalling their software."
We hope this helps. Let us know if we can assist with anything else at all. Take care.