After upgrade to MacOS Mojave, I cannot login or connect to App Store.

I just spent four hours trying to figure out this **** problem and tried several things.

Here is the easy answer:

Never mind, just figured out an easier way to resolve this:

1. Spotlight > System Information.
2. In the lefthand column, locate Software > Applications.
3. Find "App Store" in the list. If there are two versions, click the older one and identify its location.
4. Navigate to that location in Finder and confirm (via right click > Get Info) that it's the older version. Delete it.

Voila!

Scroll down and see if you see an older App Store, drag to trash. I had two App Store Apps in this folder, one older and the new one that came with the Mojave update. Kept the new, trashed the old. Then everything worked great.

Hi Frank,

this thread was one of the first results I got from google when I was looking for my problem. So I wanted to post my solution here so that maybe others can find it: I had to disable the proxy configuration with .pac file.

I really thought your solution would work for me too, but unfortunately no, on multiple MBP Retina 13" that had been wiped and fresh installed with Mojave 10.14.3 for new deployments. And tried all the other solutions suggested in many other locations.

BUT, updating to the v5, and now v6, Betas of 10.14.4 has fixed it (didn't try any earlier betas, sorry, so can't speak for those).

SUCCESS!

Source of the problem was definitely a bug in the app itself, I reckon.

Cheers!

I had the same problem since last three days, I have gone through several blogs on this nothing worked for me. today after reading a blog, first I have tried login to iTunes and I have logged in and open the App Store it just opened fine and tried to login to App Store finally I am in. it worked fine.

Hope this can help some one.

Thank you.

The same happened with me. I just stopped my anti-virus and started App Store and it worked. After that I started the anti-virus and it didn't stop the App Store again.

I unchecked the checkbox in proxy settings of the physical network adapter for „proxy configuration file“ (sorry am on mobile, the first is proxy autodetection, you want to uncheck the second one)

I was experiencing this issue until this morning and now it seems to have been resolved. I'm not sure if it was fixed by something I did or if it got fixed on Apple's end, but here are the steps I followed just in case:

• Open Keychain Access app
• Select "System Roots" keychain and "Certificates" category
• Find the "Apple Root CA" entry
• Open the certificate, expand "Trust", switch to "Never Trust", close the certificate
• Re-open the certificate, expand "Trust", switch to "Use System Defaults", close the certificate
• Do the above two steps for every "Apple Root CA" entry, "Apple Root Certificate Authority", and "Developer ID Certification Authority" certificate

Essentially, this is resetting the Trust settings for any Apple-related certificates. After I did this, I was able to view my account in the App Store app instead of seeing the "Cannot Connect to App Store" message. I was also able to add my Apple Pay card to the system again (this was not working before).

I'm still not able to install apps from the App Store, but that may be a separate issue.

Yes, a number of people in the thread have reported this to Apple. I've been back and forth with Support and their Engineering team and have found a partial solution to a problem that I was having (High Sierra App Store co-existing with the Mojave App Store, in a folder called "Previous Content"):

• The folder couldn't be deleted, so I rebooted into Restore mode (command-R while starting up).
• From the Utilities menu, I opened Terminal and disabled System Integrity Protection by typing the following in the window:
• csrutil disable
• Then pressing enter.
• Rebooting allowed me to delete the previous version of the App Store along with Safari, etc.
• Rebooting again, after deleting and emptying the Trash, restored some of the panes in the App Store:

Sadly, though, I still can't connect to the App Store.

So, perhaps partway to a solution but not there yet. I'll update as soon as a solution is found, if I find one.

SIP can be restored using the same process but with the command csrutil enable, FYI.

I was able to get the App Store to work by booting my Mac into Safe Mode (hold down the shift key until you see the Apple logo). Right now the App Store only works for me in Safe Mode so there's a conflict someplace. After I boot back into normal mode my MacBook once again cannot connect to it.

So I created an additional ADMIN acct and App store works great in that account, when I go back to main acct back to same issues everyone is having here. There must be a way to see differences in accts to see what need to be modified.

The first step is to check for connection, check your connection via iTunes Store and if it works means your connection is fine. If it is an update then this happen more likely the update has some flaws. Do a reinstall of the Mac OS of course before that backup first.

Little Snitch (my third party network filter) issued an app update today that correct the problem with the app store invalid code signature. After restarting both my mac and the app store app, my ability to connect to the app store has been restored. I'm a happy camper again!

I hope everyone struggling with a different app store issue than mine find an equally quick fix.

Try the following steps, If you haven't tried.

1. Logout from iTunes if logged in.

2. Shutdown your Mac.

3. Power on your Mac, open iTunes and login , once logged in, open App Store and check.

Let me know once you try this.

Thank you.

Further update:

Navigating to /var/db/crls and deleting all of the files in there, followed by rebooting my machine, restored the ability to update and install apps in the App Store.