I don’t know why twitter card doesn’t work at all since I have migrated to new server : https://twitter.com/flickshot_fr/status/1044619154156920833
Twitter validator results :
ERROR: Fetching the page failed because other errors.
Unable to render Card preview
Url tested for instance : https://flickshot.fr/en/article/flusha-officiellement-transfere-chez-cloud9/5ba78da4da07e
Thanks !
According to Twitter's Cards troubleshooting post the most common cause of that issue is a misconfiguration with SSL.