Unable to get a new token from refresh_token

Hello,

Yesterday I had a problem with Adobe Sign API when my app tried to get a new token from the refresh_token, I received this error: 'Required option not passed: "access_token"' and when I tried to get a bit more details from the library I used, I get this error from a description: "invalid refresh token".

I have 3 different environments (local, QA, production) and every environment encountered the same problem at the same time, this is really weird.

I can see a post on the forum with a similar problem (Getting invalid refresh token after several days, why is the refresh token expiring? ) but it was posted on April 2015 and 'resolved' in September 2015.

To correct this, I deleted all the token from the cache of my app and created a new connexion. It worked but I don't know where this error comes from and how I can found a solution to it the next time it happens.

I'm using Laravel 5.5 and this package (kevinem/adobe-sign-laravel - Packagist) to handle the connexion. I also had some troubles with this library but the issues may not be related.

Someone had the same problem recently or may help me to figure this out?

Thanks.