The Adobe Sign remote application authorization configured is invalid. Please go to the Adobe Sign Admin page and reauthorize the Adobe Sign application. Contact your Administrator for assistance.

You need to provide more info, like you are working in Salesforce and have installed the manage package and configured it and now trying to send an agreement record for signature.

My suggestion would be to remove Adobe Sign managed package from your org. (assuming it's not a production org)

register for a new Adobe Sign trial via this link:

https://acrobat.adobe.com/us/en/sign/free-trial-global/salesforce.html​

It's important to use this link as it ensures your Adobe Sign account gets configured properly for SFDC use.

You'll need to use a different email address than the one you initially signed up with though.