Unexpected error when attempting to sign via Docus

Question

We are automating scripts with Selenium, part of which is to sign a document with document. There is a docusign community forum but we just have a demo docusign account with one user, and I do not think that can send email to the community, so I thought I could ask here.

We are getting the envelope ID of a document, and then requesting the page and logging in. This is the URL:

 https://XXXdemo.docusign.com/documents/details/{ENVID}"

(I used XXX here for the first three characters for security). Also, I replace {ENVID} with the actual envelope ID.

This has been working, and still is kind of working. We do signs and advances, etc. Often now, in the middle of a sequence of steps (signing, advancing, etc) we get the login page again and the error message: Invalid Managed Token ID and / or secret (see attached image).

I did talk to some developers who told me to clear the cache before running the test. The only problem is that our Selenium tests (which are running in Chrome) start with a completely new, empty cache, bookmarks, etc.

I thought that maybe the envelope id was expiring, but a developer said he did not believe that was the case. Any suggestions what could be happening?

Specifics:

 - We create a document in Salesforce and send it to Docusign for signature.

 - We are using Selenium, Java and the latest version of Chrome.

 - This appears to happen at different Docusign places, and sometimes not at all.  Often happens when clicking "sign"

 - A google search for the error message returned only two results, neither of which was too helpful.

 - The picture below is after having signed in and running for a while.