# Could not check for JavaScript support. Please check manually if your webserver serves \`.mjs\` files using the JavaScript MIME type **URL:** \ **Category:** ℹ️ Support\ **Tags:** nc28, mjs, setup\_warning\ **Created:** [February 20, 2024, 7:00pm UTC](https://help.nextcloud.com/t/could-not-check-for-javascript-support-please-check-manually-if-your-webserver-serves-mjs-files-using-the-javascript-mime-type/182321 "2024-02-20T19:00:14Z")\ **Posts on this page:** 1\ **Showing post:** 12
**Author:** ![henningsieh](https://help.nextcloud.com/user_avatar/help.nextcloud.com/henningsieh/32/50472_2.png) [@henningsieh](https://help.nextcloud.com/u/henningsieh)\ **Post date:** [March 7, 2024, 2:29am UTC](https://help.nextcloud.com/t/could-not-check-for-javascript-support-please-check-manually-if-your-webserver-serves-mjs-files-using-the-javascript-mime-type/182321/12 "2024-03-07T02:29:45Z")
Hey Cloud workers 🙂 👋 This error has, contrary to the announcements, not been fixed in v 28.0.3, since 28.0.2 the error is still the same. **This Security & setup warnings look exactly the same in 28.0.3 again.** Please have a look at [RC5 of Nextcloud 28.0.2](https://help.nextcloud.com/t/rc5-of-nextcloud-28-0-2/180292/8). > [@RC5 of Nextcloud 28.0.2](https://help.nextcloud.com/t/rc5-of-nextcloud-28-0-2/180292/8): > > after updating to 28.0.2, but I do not understand how to resolve this one: > > ![grafik](https://help.nextcloud.com/uploads/default/original/3X/e/e/eee6e978ae29cd8625b7a4b809d56a1b44ea466c.png) – My Nextcloud installation runs in Docker and has a nginx reverse proxy in front of it: > **docker-compose:** > > ```auto > version: '3' > > volumes: > nextcloud: > db: > > networks: > nextcloud_network: > external: false > > services: > app: > image: nextcloud:28.0.3 > container_name: nextcloud28-app > restart: unless-stopped > hostname: cloud.sieh.org > ports: > - 127.0.0.1:8080:80 > healthcheck: > test: ["CMD", "curl", "-fs", "-S", "--max-time", "2", "http://localhost:80"] > interval: 60s > timeout: 5s > retries: 3 > links: > - db > volumes: > - /root/nextcloud28/html:/var/www/html > - /root/nextcloud28/data:/var/www/html/data > environment: > - MYSQL_PASSWORD=*** > - MYSQL_DATABASE=nextcloud28 > - MYSQL_USER=nextcloud > - MYSQL_HOST=db > - REDIS_HOST=redis > networks: > - nextcloud_network > > db: > image: mariadb:latest > container_name: nextcloud28-mariadb > restart: unless-stopped > command: --transaction-isolation=READ-COMMITTED --log-bin=binlog --binlog-format=ROW --innodb-file-per-table=1 --skip-innodb-read-only-compressed > volumes: > - /root/nextcloud28/mysql:/var/lib/mysql > environment: > - MARIADB_AUTO_UPGRADE=1 > - MARIADB_DISABLE_UPGRADE_BACKUP=1 > - MYSQL_ROOT_PASSWORD=*** > - MYSQL_PASSWORD=*** > - MYSQL_DATABASE=nextcloud > - MYSQL_USER=nextcloud > networks: > - nextcloud_network > healthcheck: > test: "/usr/bin/mariadb --user=root --password=*** --version" > interval: 60s > timeout: 5s > retries: 3 > > redis: > image: redis:alpine > container_name: nextcloud28-redis > volumes: > - /root/nextcloud28/redisdata:/data > networks: > - nextcloud_network > restart: unless-stopped > > ``` > **nginx domain conf:** > > ```auto > server { > server_name cloud.sieh.org; > > listen [::]:443 ssl; > listen 443 ssl; > > include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot > ssl_certificate /etc/letsencrypt/live/cloud.sieh.org-0001/fullchain.pem; # managed by Certbot > ssl_certificate_key /etc/letsencrypt/live/cloud.sieh.org-0001/privkey.pem; # managed by Certbot > ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot > > add_header Strict-Transport-Security "max-age=15768000; includeSubDomains; preload;" always; > > client_max_body_size 512M; > > location / { > > include mime.types; > types { > text/javascript js mjs; > } > > proxy_set_header Host $host; > proxy_set_header X-Real-IP $remote_addr; > proxy_set_header X-Forwarded-Proto https; > proxy_set_header X-Forwarded-Host $remote_addr; > proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; > > proxy_buffers 16 4k; > proxy_buffer_size 2k; > > proxy_pass http://127.0.0.1:8080/; > } > > location /.well-known/carddav { return 301 $scheme://$host/remote.php/dav; } > location /.well-known/caldav { return 301 $scheme://$host/remote.php/dav; } > > } > > ``` As you see, I have also included the mime.types, as I got this advice from @koelle25: > [@RC5 of Nextcloud 28.0.2](https://help.nextcloud.com/t/rc5-of-nextcloud-28-0-2/180292/10): > > see this example config from the nextcloud/docker repo … but the error still persists, I have no Idea anymore. ☹ > **The \*curl esm-test.mjs\* thing looks like this:** > > ```auto > root@vmd104158:~# curl -I https://cloud.sieh.org/apps/settings/js/esm-test.mjs > HTTP/1.1 200 OK > Server: nginx > Date: Thu, 07 Mar 2024 02:20:09 GMT > Content-Type: text/javascript > Content-Length: 109 > Connection: keep-alive > Vary: Accept-Encoding > Referrer-Policy: no-referrer > X-Content-Type-Options: nosniff > X-Frame-Options: SAMEORIGIN > X-Permitted-Cross-Domain-Policies: none > X-Robots-Tag: noindex, nofollow > X-XSS-Protection: 1; mode=block > Last-Modified: Thu, 07 Mar 2024 01:58:40 GMT > ETag: "6d-613086a1609f2" > Accept-Ranges: bytes > Vary: Accept-Encoding > Cache-Control: max-age=15778463 > Strict-Transport-Security: max-age=15768000; includeSubDomains; preload; > > root@vmd104158:~# > > ``` I have often read something about “selfsigned certs” in this context, but it’s unpossible, that this problem has anything to do with “selfsigned certs”, because I **do not have any** “selfsigned certs”. I only have a letsencrypt cert, which is used by the outer nginx reverse proxy. **The nextcloud DOES NOT KNOW ANYTHING about this SSL.** I still think, js/mjs HAS NOTHING TO DO with ssl encryption, because NO OTHER FILE TYPE has this or even a similar problem. And… > [@salto\_lenin](#): > > Thank You!!! > > yes, turns out, had to edit /etc/hosts file by removing 127.0.0.1 … I do not understand this solution. ☹ What do I have to change in my nginx conf? (see above!) Please help me to get rid of this anyoing warning!? 😮‍💨 --- _[View the full topic](https://help.nextcloud.com/t/could-not-check-for-javascript-support-please-check-manually-if-your-webserver-serves-mjs-files-using-the-javascript-mime-type/182321)._