I am using the Let's Encrypt module for Drupal 7, trying to follow the instructions outlined here by Redfin Solutions, to install free SSL on Acquia's servers, but I've run into a curious problem:

Each time I generate the challenge using the certbot manual mode (using sudo certbot certonly --manual -d example.com), It tells me the key authorization file from the server does not match the challenge.

Failed authorization procedure. example.com (http-01): urn:acme:error:unauthorized :: The client lacks sufficient authorization :: The key authorization file from the server did not match this challenge
[TBgi6LPQfn7SJOTMcA67Crjrb_wGI9WKL4XAE-a17io.x6url1PIuenF6WDlPejYYJM2E4fg3wOFn8t4ghXDAGI] != [ TBgi6LPQfn7SJOTMcA67Crjrb_wGI9WKL4XAE-a17io.x6url1PIuenF6WDlPejYYJM2E4fg3wOFn8t4ghXDAGI]


  • The following errors were reported by the server:
    Domain: example.com
    Type: unauthorized
    Detail: The key authorization file from the server did not match this challenge [TBgi6LPQfn7SJOTMcA67Crjrb_wGI9WKL4XAE-a17io.x6url1PIuenF6WDlPejYYJM2E4fg3wOFn8t4ghXDAGI] != [TBgi6LPQfn7SJOTMcA67Crjrb_wGI9WKL4XAE-a17io.x6url1PIuenF6WDlPejYYJM2E4fg3wOFn8t4ghXDAGI]

To fix these errors, please make sure that your domain name was entered correctly and the DNS A record(s) for that domain contain(s) the right IP address.

As you can see, the second one (which is the one in the server), shows with a linefeed at the start. I am baffled by this, I went into the module and it just displays the value saved in a system variable, which I verified in the database. Other than that they seem to be identical, I have not been able to go further. Has anybody experienced anything similar? Any suggestions on how to fix this?

  • Update: I tried this in a different (simpler, non Aqcuia) instance, and the line feed does not show. Will try with a different Acquia site. Commented May 23, 2017 at 18:20
  • Update: Tested a different Acquia site and works without issue. The problem seems to be site specific. Commented May 23, 2017 at 19:32
  • Update: Problem seems theme related. Switched themes and problem goes away. Commented May 23, 2017 at 20:07
  • Finally: a file in the theme had a blank line, should be empty. Everything in order now. Commented May 23, 2017 at 23:02

1 Answer 1


Turns out the module works like a charm, the problem was theme related, sending out a blank line at the top of the page: this was enough to confuse Let's Encrypt when running the validation of the site.

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