502 Bad Gateway after Discourse update
problem: ssl certificate error
how to check:
tail /var/discourse/shared/standalone/log/var-log/nginx/error.log
if there's
cannot load certificate "/shared/ssl/<domain>_ecc.cer": PEM_read_bio_X509_AUX() failed (SSL: error:0909006C:PEM routines:get_name:no start line:Expecting: TRUSTED CERTIFICATE)
solution:
rm /var/discourse/shared/standalone/ssl/*_ecc.*
rm -rf /var/discourse/shared/standalone/letsencrypt/*_ecc/