Apple is constantly updating their terms of agreement, and in order to be able to update a new version of your app or make changes to it, you will need to make sure all agreements on your account are accepted.
Before you proceed, it is important to note that only the account owner, the person who originally enrolled for the Apple Developer program, will be able to accept pending agreements.
Checking for pending agreements
To check if you have any pending agreements, log in to the account owner account here: https://developer.apple.com/account
If your main agreement is pending you should immediately see a notice at the top of the screen as soon as you login, just click the "Review agreement" button:
You will then be prompted to read and accept the agreement, make sure to read it through and click the "Agree" button, as you can see here:
You will see a list with all agreements, accepted or not:
Note on the “Paid Apps” agreement
IMPORTANT! Sometimes you will see a "Paid Apps" agreement pending acceptance, even if you don't have any paid apps. Apple requires that agreement to be accepted in order to allow changes to your account and new versions to be uploaded, so even if you don't have a paid app, make sure to accept the agreement.
After accepting the "Paid Apps" agreement, you might also be asked to provide Banking and Tax information, in this case you can simply ignore that request. Accepting the agreement is all you need to do to re-enable the app uploads and account changes, so don't worry.
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