I'm creating a very simple Power-Up which should add a button to the board.
I followed the Power-Up tutorial on Trello and created the necessary files over https and added the Power-Up in the admin section.
When I go to any board and try to activate the Power-Up, I can see it in the list, but with an error message "Unable to load Power-Up"
My question is : "is there any way to debug this ?"
Otherwise could anyone have a look to my files and tell me if something looks wrong ?
Thanks in advance for your help
Looks like your server doesn't set the Access-Control-Allow-Origin header. See https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS
You need to add the header to allow trello.com to load your powerup from an scripting request.
I added the header but this still does not work.
I've imported the Trello Power-up template code on my server and it still does not work, which shows that the server is the issue.
Specially seeing that if I import the same manijest.json file from github it works fine.
I've checked both servers HTTP headers but I don't manage to find where this could come from.
Do you have any idea ?
Status: HTTP/1.1 200 OK
Date: Sat, 22 Jul 2017 09:46:51 GMT
Last-Modified: Sat, 22 Jul 2017 09:38:29 GMT
Content-Type: application/json; charset=utf-8
Strict-Transport-Security: max-age=16000000; includeSubDomains; preload