Incorrect Apple ID after Software Update to iOS9.3

Most of the time this happens when folks edit their primary apple id e-mail address without first signing out of iCloud on their phone - the phone stays signed in with the old e-mail adress. Here's the latest from apple If you can't activate your iPhone, iPad, or iPod touch after installing iOS 9.3 - Apple Support

If you can sign into iCloud.com AND see your phone under All Devices, you can remove it from account as a last resort.

I have been having the same issue and I have been dealing with this all day. 😟 Here's what I did: I installed the new iOS 9.3 version this morning, after it was done installing it came to this "Activate iPhone" screen which I have never came across before. The previous installations never asked me that. So, it asked me "This iPhone is linked to an Apple ID. Enter the Apple ID and password that were used to set up this iPhone. (d●●●●●@icloud.com)" The BIG problem is that I cannot remember the AppleID and the Password 😠

Therefore, I went to to icloud.com and created a new AppleID and password to see if I can access the home screen. I typed in the new Apple ID and password and my iPhone 4s didn't take it. Now, I am stuck. I tried to access thru iTunes and ran into the same issue and the same message, "This iPhone is linked to an Apple ID. Enter the Apple ID and password that were used to set up this iPhone. (d●●●●●@icloud.com)" came up,

Oh, I tried to log into icloud with my new account and it came across an error message, too. 😟 So, I can't proceed in fixing my issue.

Any solutions to this issue?

I have the same problem from doing the update. I have tried the fixes in your link but it still wont activate my phone. Any more suggestions to resolve this issue.