Nginx: [emerg] cannot load certificate after I deleted the certificate - nginx

Question

I generated an SSL certificate on one of my subdomains. I then tried to delete/revoke the certificate using the command certbot delete. A little terminal menu popped up asking me what certificate I would like to delete. I deleted the one I wanted to delete. Now, when running sudo nginx -t I am getting error messages saying:
nginx: [emerg] cannot load certificate "/etc/letsencrypt/live/app.mydomain.nl/fullchain.pem": BIO_new_file() failed (SSL: error:02001002:system library:fopen:No such file or directory
I guess the certbot delete command did not fully delete the certificate or something? I am clueless what to do right now...

Answer 1

You probably used the command $ certbot --nginx and your nginx config file was edited to look for the certificate:
server{
server_name [your_domain];
location /static {
...
}
location / {
...
}
listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/[...]; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/[...]; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/[...]; # managed by Certbot
}
server{
if ($host = [your_domain]) {
return 301 https://$host$request_uri;
} # managed by Certbot
server_name [your_domain];
listen 80;
return 404; # managed by Certbot
}
The $ certbot delete will not change it back, so you have to delete the part related to the certificated and change the server_name to your ip address, so it will look like:
server{
server_name [your ip];
location /static {
...
}
location / {
...
}
}