App Store sign-in issue prevents app updates on MacBook Pro running Mojave

I have a problem on an Intel based Mac.

The computer is a 2016, 1TB, Intel based Macbook Pro.

The operating system is Mojave 10.14.6

When using the App Store app it wont let me update any previously purchased applications. When I press the Update All button in App Store a drop down tab tells me that need to sign in to my Apple account (even though I am already signed in according to the iTunes app). In the App Store I keep being offered the drop down tab to sign in to my Apple account but when I enter the correct password it ignores my request. The Sign In tab keeps reappearing with the password section blank. I fill in the correct password and the same thing happens again.

At one point after a few attempts an error label came up which said the following…

“An unexpected error occurred while signing in. The server gave an error during download:400 Bad Request”.

I have no idea what that means.

Before this problem occurred the computer had not been opened for a few weeks and needed recharging but that’s not unusual. Prior to that period of inactivity everything was working as it should and I was able to update apps in the App Store.

As I mentioned above I believe that I am currently signed into my Apple account on this machine despite what the App Store says. In the iTunes app under the Account tab I am offered the option to “Sign Out” of my Apple account, therefore I must be signed in.

I have also tried rebooting the mac several times since the problem occurred but that has made no difference.

I’ve purposely kept the operating system at 10.14.6 because I still really like the iTunes music app, as well as having a few third party apps installed for which there are no upgrades available for silicone based models.

So the bottom line is that I really want to get this problem resolved without having to update the operating system from Mojave.

And one other thing… I am signed in to my Apple account on several other Apple devices using the same email address and the same password. I know the details that I am trying to enter are correct. The password should be as valid to log me in to my account in the App Store as it is on my other devices.

Any help or suggestions would be much appreciated.

Thank you.

MacBook Pro 15″, macOS 10.14

Posted on Aug 26, 2026 11:57 AM

Top-ranking reply

Grant Bennet-Alder

Level 10

145,461 points

Posted on Aug 28, 2026 3:02 PM

Exactly what version of MacOS and Safari appears to make a Huge difference.

SSL to TLS:

In June 2015, Researchers at standards organizations formally declared that Secure Socket Layer (then SSL 3) Internet Encryption was not nearly as secure as was thought, and needed to be replaced. SSL Versions 1 and 2 had already been deprecated by that time,

Early versions of Transport Layer Security (TLS) were already available in many Browsers. Over a remarkably brief period of time, sites tightened requirements for what was acceptable for encryption, and refused connections from browsers that could only offer SSL 3.

Apple issued Safari version 9 in 10.11 El Capitan version of MacOS, which included an early version of TLS encryption. Safari 9 was later provided by Security Update into the two previous versions of MacOS. 10.10 Yosemite and 10.9 Mavericks, PROVIDED you applied all available software updates.

MacOS versions older than those can not make secure [httpS:] connections on the Internet, because by 2016 standards, your proffered encryption (SSL) is considered inadequate.

————

Researchers continued to work on improving encryptions standards. We now find ourselves at another time when a lot of stuff has become untenable on the modern Internet. In October 2018, Apple, Google, Microsoft, and Mozilla jointly announced they would deprecate TLS 1.0 and 1.1 in March 2020

TLS 1.0 and 1.1 support in NEW versions of Safari was deprecated starting in March 2020, as part of a broader move by major browsers to enhance security by transitioning to more secure versions like TLS 1.2 and TLS 1.3. This change was made to protect web traffic and improve data security.

TLS 1.3 first became available in the version of Safari issued in MacOS 11 Big Sur, and was said to be retrofit into older versions back to 10.14.4 Mojave, but only by applying ALL available security updates.

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16 replies

xDJZak

Level 1

20 points

Aug 28, 2026 4:15 PM in response to Grant Bennet-Alder

Ah I didn’t see, but no, I did a fresh install just in case

App Store sign-in issue prevents app updates on MacBook Pro running Mojave