Guillermo Madero

You could try by clearing all the caches:

Site admin > Development > Purge all caches

https://docs.moodle.org/25/en/Developer_tools

You could also see if the badge.png file is at the moodle pix/i folder:

moodle/pix/i

I had to leave.. but I'm back...

Continuing with the "http" to "https" changes required... also:

At moodle/badges/lib/backpacklib.php, line: 33.

At moodle/lib/badgeslib.php, lines: 1301 (a comment line), 1309.

At moodle/lang/en/badges.php, lines: 82, 209, 229, 344.

Cheers!

I have a Moodle 2.5 site that works with the Spanish language packages (es & es_mx) and I recently enabled the badge functionality and awarded the first badge.

The problem was that the participant couldn't send her badge to the Mozilla Backpack.

A particular thing that made this issue frustrating, was that I first made certain that I had a clear picture and all the correct steps by testing the process at a local copy of the site with my own registered email at the backpack, and the whole process went without problems. However, when my site's participant did the same, the process failed.

After asking her for her passwords I tried both, sending the badge from Moodle itself and uploading it directly, and in both cases I efectively received either a cryptic message, a "connection problem", a "badge not belonging to the earner" or a "could not get assertion: invalid http response" error message.

In despair, I made a full site backup, awarded a badge to a test student (with my registered email at the backpack) and when I tried to send the badge... the process went without issues!

So I have the same Moodle live site and the same badge being awarded, and the only difference seemed to have been in that one user has been previously awarded (at other sites) and the other has not (it is her first badge ever).

The solution came after noticing that at the Moodle Backpack Settings page ("Configuraciones de mochila", in Spanish), the URL text said, "http://backpack...", which led me into looking into the Spanish language packages.

As strange as it may sound, after I changed all the "http" references, everything worked fine 

At moodledata/lang/es/badges.php
search for: http://backpack.openbadges.org
replace with: https://backpack.openbadges.org
// lines: 86, 208, 227, 344

At moodledata/lang/es_mx/badges.php
search for: http://backpack.openbadges.org
replace with: https://backpack.openbadges.org
// lines: 82, 202, 221, 321

Cheers!

Mine is from a reunion I had a few years ago with my sisters and my brother.

I chose it because the expression of my face doesn't look as serious as it usually does  

Hi Visvanath,

Thanks! I was here trying to solve a few small details I had with my Moodle site and well, I just took a few minutes to answer a post... old habits, old habits   These Moodle forums are like an addiction  

How is everything?Moodle 3.0? Wow! Time flies!

Cheers!