我正试图在我的覆盆子pi上建立一个云。我正在关注本教程https://canox.net/2016/06/die-eigene-cloud-mit-dem-raspberry-pi-und-nextcloud/ 在用nextcloud替换nginx配置并为let加密创建证书后，我重新启动了服务
sudo systemctl restart nginx.service
我得到了
Job for nginx.service failed because the control process exited with error code.
See "systemctl status nginx.service" and "journalctl -xe" for details.
systemctl status nginx.service：
● nginx.service - A high performance web server and a reverse proxy server
Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: en
Active: failed (Result: exit-code) since Sun 2018-06-17 10:56:58 UTC; 37s ago
Docs: man:nginx(8)
Process: 619 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process o
Jun 17 10:56:58 raspberrypi systemd[1]: Starting A high performance web server a
Jun 17 10:56:58 raspberrypi nginx[619]: nginx: [emerg] BIO_new_file("/etc/letsen
Jun 17 10:56:58 raspberrypi nginx[619]: nginx: configuration file /etc/nginx/ngi
Jun 17 10:56:58 raspberrypi systemd[1]: nginx.service: Control process exited, c
Jun 17 10:56:58 raspberrypi systemd[1]: Failed to start A high performance web s
Jun 17 10:56:58 raspberrypi systemd[1]: nginx.service: Unit entered failed state
Jun 17 10:56:58 raspberrypi systemd[1]: nginx.service: Failed with result 'exit-
lines 1-13/13 (END)
● nginx.service - A high performance web server and a reverse proxy server
Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Sun 2018-06-17 10:56:58 UTC; 37s ago
Docs: man:nginx(8)
Process: 619 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process on; (code=exited, status=1/FAILURE)
Jun 17 10:56:58 raspberrypi systemd[1]: Starting A high performance web server and a reverse proxy server...
Jun 17 10:56:58 raspberrypi nginx[619]: nginx: [emerg] BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem"
Jun 17 10:56:58 raspberrypi nginx[619]: nginx: configuration file /etc/nginx/nginx.conf test failed
Jun 17 10:56:58 raspberrypi systemd[1]: nginx.service: Control process exited, code=exited status=1
Jun 17 10:56:58 raspberrypi systemd[1]: Failed to start A high performance web server and a reverse proxy server.
Jun 17 10:56:58 raspberrypi systemd[1]: nginx.service: Unit entered failed state.
Jun 17 10:56:58 raspberrypi systemd[1]: nginx.service: Failed with result 'exit-code'.
journalctl -xe：
Jun 17 11:05:33 raspberrypi sudo[696]: pi : TTY=pts/0 ; PWD=/home/pi ; USER=root ; COMMAND=/bin/nano /etc/nginx/sites
Jun 17 11:05:33 raspberrypi sudo[696]: pam_unix(sudo:session): session opened for user root by pi(uid=0)
Jun 17 11:09:00 raspberrypi systemd[1]: Starting Clean php session files...
-- Subject: Unit phpsessionclean.service has begun start-up
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- Unit phpsessionclean.service has begun starting up.
Jun 17 11:09:01 raspberrypi CRON[749]: pam_unix(cron:session): session opened for user root by (uid=0)
Jun 17 11:09:01 raspberrypi CRON[753]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; t
Jun 17 11:09:01 raspberrypi CRON[749]: pam_unix(cron:session): session closed for user root
Jun 17 11:09:01 raspberrypi systemd[1]: Started Clean php session files.
-- Subject: Unit phpsessionclean.service has finished start-up
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- Unit phpsessionclean.service has finished starting up.
--
-- The start-up result is done.
Jun 17 11:09:36 raspberrypi sudo[696]: pam_unix(sudo:session): session closed for user root
Jun 17 11:09:36 raspberrypi systemd[1]: Starting Cleanup of Temporary Directories...
-- Subject: Unit systemd-tmpfiles-clean.service has begun start-up
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- Unit systemd-tmpfiles-clean.service has begun starting up.
Jun 17 11:09:36 raspberrypi systemd[1]: Started Cleanup of Temporary Directories.
-- Subject: Unit systemd-tmpfiles-clean.service has finished start-up
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- Unit systemd-tmpfiles-clean.service has finished starting up.
--
-- The start-up result is done.
Jun 17 11:09:45 raspberrypi sudo[767]: pi : TTY=pts/0 ; PWD=/home/pi ; USER=root ; COMMAND=/bin/systemctl restart ngi
Jun 17 11:09:45 raspberrypi sudo[767]: pam_unix(sudo:session): session opened for user root by pi(uid=0)
Jun 17 11:09:45 raspberrypi systemd[1]: Starting A high performance web server and a reverse proxy server...
-- Subject: Unit nginx.service has begun start-up
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- Unit nginx.service has begun starting up.
Jun 17 11:09:45 raspberrypi nginx[773]: nginx: [emerg] BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem"
Jun 17 11:09:45 raspberrypi nginx[773]: nginx: configuration file /etc/nginx/nginx.conf test failed
Jun 17 11:09:45 raspberrypi systemd[1]: nginx.service: Control process exited, code=exited status=1
Jun 17 11:09:45 raspberrypi systemd[1]: Failed to start A high performance web server and a reverse proxy server.
-- Subject: Unit nginx.service has failed
-- Defined-By: systemd
-- Support: https://www.debian.org/support
--
-- Unit nginx.service has failed.
--
-- The result is failed.
Jun 17 11:09:45 raspberrypi systemd[1]: nginx.service: Unit entered failed state.
Jun 17 11:09:45 raspberrypi systemd[1]: nginx.service: Failed with result 'exit-code'.
Jun 17 11:09:45 raspberrypi sudo[767]: pam_unix(sudo:session): session closed for user root
error.log中：
Job for nginx.service failed because the control process exited with error code.
See "systemctl status nginx.service" and "journalctl -xe" for details.
2018/06/17 10:33:17 [emerg] 17940#17940: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:35:44 [emerg] 17974#17974: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:37:34 [emerg] 18038#18038: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:40:42 [emerg] 18124#18124: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:41:39 [emerg] 18145#18145: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:43:34 [emerg] 18159#18159: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:44:18 [emerg] 18185#18185: "upstream" directive is not allowed here in /etc/nginx/sites-enabled/default:1
2018/06/17 10:44:37 [emerg] 18201#18201: "upstream" directive is not allowed here in /etc/nginx/sites-enabled/default:1
2018/06/17 10:46:09 [emerg] 18221#18221: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:49:46 [emerg] 18235#18235: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fo$
2018/06/17 10:46:22 [emerg] 526#526: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fopen:$
2018/06/17 10:56:58 [emerg] 619#619: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fopen:$
2018/06/17 11:09:45 [emerg] 773#773: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fopen:$
2018/06/17 11:18:12 [emerg] 865#865: BIO_new_file("/etc/letsencrypt/live/quinter.spdns.org/fullchain.pem") failed (SSL: error:02001002:system library:fopen:$
我在这里有点新意，我真的希望有人可以帮助我。您可以告诉我需要提供哪些信息以期找到解决方案。