Unable to change iCloud+ storage plan

n1dhu9,

We'd like to learn more to see how we can help.

You mentioned your Mac is running macOS X. Which Mac do you have and which exact macOS version is listed in the Apple menu () > About This Mac? Are you entering the password for the same Apple ID that's listed in System Preferences > Apple ID?

Let's also be sure you're following these steps exactly:

How to upgrade on your Mac

1. Choose Apple menu  > System Preferences, then click Apple ID.

2. Click iCloud.

3. Click Manage in the lower-right corner.

4. Click Change Storage Plan or Buy More Storage, and choose a plan.

5. Click Next and enter your Apple ID password.

You'll find these steps and more information here: Upgrade to iCloud+ - Apple Support

Let us know what you find.

Thanks!

In the discussion you mentioned -

I am using a password manager and am copy-pasting the password, but I have also tried to enter it manually several times.

Click on finder > applications , you will find this password manager app right click over it and move to trash , restart the Mac and empty the trash its conflicting iCloud Keychain and Mac system preferences How to uninstall apps on your Mac – Apple Support

To delete complete contents of this app .

Set up iCloud Keychain Set up iCloud Keychain - Apple Support

Autofill your username and password in Safari on Mac - Apple Support

Change Passwords preferences on Mac - Apple Support

This method written below is for Mac OS catalina 10.15,7

Open system preferences and click on users and groups , open the pad lock by entering admin name and password ( in case if it's an admin account ) , select login items , if you see unknown app select it and click on subtract sign to get deleted .

In system preferences itself click on Security and privacy , click on Accessibility then privacy select the unknown app click on subtract sign to get deleted .

Click on finder and search in Applications and download folder . 

The next step would be enter in System Library .

Click on Finder , take cursor on top menu bar click on Go - Computer - Macintosh HD - Library 

You have to manually search app in some folders where they reside .

1.Application Support 

2.Caches 

3.LaunchAgents

4.LaunchDaemons

5.Logs 

6.PriviledgedHelperTools

7.Startup-items

8.Receipts

9.Preferences - the plist of app is to be removed .

10.Extensions

11.Frameworks

12.internet Plug -ins

13.Input Methods

14.ScriptingAdditions

Enter in User library - click on finder > Go > hold option key > Library

Search app contents in folders 

1.Application Support 

2.Caches

3.Cookies

4.Safari

5.Logs

6.Saved Application State

7.LaunchAgents

8.Internet Plug -ins

9.Input Methods

10.Preferences - com.apple.xxx.plist ( xxx - denotes the app .plist ) 

11.Containers are also to be checked .

 Again click on Finder - Go - Computer - Macintosh HD - System - Library - Frameworks - search the malware in Framework folder .

Right click on app from the above folders and move to the trash , restart the computer and empty the trash .

Hi n1dhu9,

Thank you for posting in Apple Support Communities! Seems like this issue may be isolated to your Mac itself so let's troubleshoot it a bit. Since attempting to upgrade the storage and getting this error message, has your Mac been restarted? Restarting can help resolve many unexpected issues we face with our devices.

To restart your Mac go to the Apple menu (  ) > Restart.

You can also confirm that your Mac is up to date and running the latest available macOS for your model. To check for any available updates:

1. Go to the Apple menu (  ) > System Preferences
2. Tap on Software Update
3. Tap Update Now or Restart Now to install if an update is available

Update macOS on Mac - Apple Support

Hope that helps!

n1dhu9,

Thanks for letting us know. Since you're still experiencing the same problem after giving the previous troubleshooting steps a try, we recommend contacting Apple Support directly so that they can work with you to find a solution.

Contact - Official Apple Support

Thank you for participating in the Apple Support Communities.

Cheers!