Please wait for System Upgrade and Extension Manager

[retrorag]

Hello,

I'm running Magento 2.3.0 and everything is working perfectly except the System --> Web Setup Wizard --> Extension Manager and System Upgrade items. After clicking on the Web Setup Wizard I see the menu with the 4 choices (Extension Manager, Module Manager, System Update and System Configuration). I can re-enter my keys and while it takes a long time it does complete without error. Extension Manager and System Upgrade display a message (either Please Wait or Checking for new version) with a spinning wheel that never ends. I do not know which logs to look in to find an explanation. 

Edit: In my Chrome console I get error 524 which is a timeout.

Any assistance would be great.

Thanks

[Manish Mittal]

Hello @retrorag 

There are many reasons why you get this issue. However, in our case, it came from custom module composer and here is how we get it solved.

Go to this file:  /setup/src/Magento/Setup/Model/PackagesData.php

Create a backup of this file before editing.

Then replace it using this file:

PackagesData

You can read more discussion about this issue here: https://github.com/magento/magento2/issues/6718

And this is where you can get this file from Magento: PackageData.php from Magento