iCloud encountered an error while trying to connect to the server

Hello preferPC,

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. Start out by checking these items, then follow the other troubleshooting in the support article if the issue persists:

"Before you change your security software's setup: 

• Make sure that the date, time, and time zone are set correctly on your computer. Learn how to update these settings on a Mac or on a PC. 
• Log in to an administrative user account, not a guest account. Learn how to do this on a PC. 
• Update to the latest version of iCloud for Windows or update to the latest version of iTunes.
• Make sure that you have the latest software on your Mac or on your PC.
• Make sure that you set up Windows Hello. Learn how to set it up. 
• Make sure that you only have one type of security software installed. If you have more than one type of security software installed, you might experience performance issues."

We hope this helps. Let us know if we can assist with anything else at all. Take care.

Update on my situation:

Turning off IPV6 allowed me to successfully see icloud.com in a browser. However, the icloud app (from the Microsoft store) didn't work. I successfully downloaded and installed it, and it didn't error our when I selected the Outlook addin from icloud preferences. However, my calendars and contacts didn't load in Outlook; also the iCloud menu in Outlook didn't appear in Outlook. I check to make sure the add-in was present and activated. Still no joy.

Based on a suggestion from another post here, I uninstalled the icloud app and installed an older version I downloaded in 2019. This version does not include sync'd passwords. However, it did properly install, it did add the Outlook add-in, and it did add the iCloud menu in Outlook.

Clearly, there is a disconnect in the current (MS Store) version of the icloud app. I hope Apple fixes the problem.

***9/2/23 UPDATE***

Prior to discovering the IPv6 suggestion, I downloaded two previous versions of iCloud Windows installer, neither of which worked. The only access I had was via Firefox. After discovering the disconnect of IPV6 suggestion, I took the following steps:

1) in Control Panel\Network and Internet\Network Connections\Change adapter settings\[right-click on wi-fi adapter]\Properties\[uncheck Internet Protocol Version 6 (TCP/IPv6)]

2) closed all apps (including Outlook)

3) rebooted

4) from Windows Start menu, launched iCloud App and was able to login with AppleID

5) checked all options desired

6) launched Outlook and confirmed Calendars and Contacts had ported over

7) launched Opera, Edge, Firefox and Chrome and was able to access and logon to iCloud.com

Many thanks to the pros that figured this out and shared. Hopeful Apple or MS can sort this out. It must embarrassing to either or both at some level, especially since both charge for so-called "plus" services.

It is possible to use IPV6. I believe the problem is to do with the Intel Killer app. This had an update in august and the problem happened since then. Disable the prioritisation engine in its settings and all works ok. No need to play around with ipv6 in network settings.

So, I followed advice from another post. I disabled the Killer Intelligence Engine in the settings for Killer Control. Stays off that way after a restart too. I have the Killer Wireless 1550i adpater in my Acer Predator laptop. That resolved all my issues. Was able to turn IPv6 back on and keep it on. It's worked for over a week now!

If you have the Intel Killer Intelligence Centre, turn off the Prioritisation Engine. This works. It will sometimes come back on after a reboot but it’s easy to turn off again.

For me, this problem started after the Killer app had its last update.

After digging through posts, chats, forums and not finding any answers, I found it. You just have to go on your iPhone/iPad/(maybe Mac too) and go Settings->Apple ID->iCloud scroll to the bottom and turn on "Access iCloud Data on the Web"

You all can maybe stop pulling your hair out now (if it works). You're welcome.

Regarding the connection error. Because it's a connection error I clicked the the secure padlock for site https://www.icloud.com/ in chrome, followed by selecting "site settings", clicked "reset permissions" and connection to icloud proceeded correctly.

On Windows 10 with iCloud app installed was unable to authenticate to icloud for last 2 weeks or so, also had lots of network errors when trying to access icloud.com. Disabled IPv6 in my Wifi network adapter properties configuration menu. Problem appears to have been resolved.

I followed your lead and disabled IPV6 in my adapter settings. Now I am able (again) to log into the iCloud app.

For me, there wasn't a problem with browsers (I primarily use Firefox 64 bit, but also Edge in a Windows 11 Pro environment.)

Thanks for sharing your tip!

I followed the suggestions of a few different replies in this thread, but the one that did work for me was turning off Killer Prioritization Engine in the Killer app. That immediately resolved it, including some of the widgets not loading when I was able to log in.

None of Gena_D solutions worked for me. The only solution that worked I found several messages below 8/29 from Miagra. Details there show that accessing with a browser that's NOT Edge may work. I just tried Firefox and accessed iCloud.com easily and all my data is visible. Agree that it's some sort of browser issue. For now, changing my default to Firefox.

After digging through posts, chats, forums and not finding any answers, I found it. You just have to go on your iPhone/iPad/(maybe Mac too) and go Settings->Apple ID->iCloud scroll to the bottom and turn on "Access iCloud Data on the Web"

You all can maybe stop pulling your hair out like I was (if it works). You're welcome :)

Did you turn off the Prioritisation Engine within the Killer Intelligence Centre app itself? I turned mine off there (within the Settings cog icon) and it has stayed off ever since.