Backend - Internal Server Error

Hi, how to correct error 500 Hestia backend login?

Debian 9

2021/07/30 07:31:42 [error] 416#0: *7 FastCGI sent in stderr: “PHP message: PHP Warning: require(vendor/autoload.php): failed to open stream: No such file or directory in /usr/local/hestia/web/inc/main.php on line 7PHP message: PHP Fatal error: require(): Failed opening required ‘vendor/autoload.php’ (include_path=’.:’) in /usr/local/hestia/web/inc/main.php on line 7” while reading response header from upstream, client: 185.212.13.101, server: _, request: “GET /login/ HTTP/1.1”, upstream: “fastcgi://unix:/var/run/hestia-php.sock:”, host: “server.robofeed.eu:8083”

Looks like there are some files missing, what happens when you do a apt update && apt install --reinstall hestia?

v-add-sys-phpmailer and check what the error is

Probably nano /etc/php/7.4/cli/php.ini and disable the functions in the warning

Unfortunately, the upgrade failed

root@server:/usr/local/hestia/web/inc# apt update && apt install --reinstall hestia
Hit:1 http://security.debian.org stretch/updates InRelease
Hit:2 https://nginx.org/packages/mainline/debian stretch InRelease
Hit:3 https://apt.hestiacp.com stretch InRelease
Hit:4 https://mirror.mva-n.net/mariadb/repo/10.5/debian stretch InRelease
Hit:5 https://packages.sury.org/apache2 stretch InRelease
Hit:6 https://packages.sury.org/php stretch InRelease
Ign:7 http://ftp.cz.debian.org/debian stretch InRelease
Hit:8 http://ftp.cz.debian.org/debian stretch-updates InRelease
Hit:9 http://ftp.cz.debian.org/debian stretch Release
Reading package lists... Done
Building dependency tree
Reading state information... Done
1 package can be upgraded. Run 'apt list --upgradable' to see it.
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  clamav-daemon
Suggested packages:
  libclamunrar apparmor clamav-docs daemon
Recommended packages:
  clamdscan
The following packages will be upgraded:
  clamav-daemon
1 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
85 not fully installed or removed.
Need to get 0 B/285 kB of archives.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
E: Internal Error, No file name for hestia:amd64
root@server:/usr/local/hestia/web/inc#

@vanThomas Check

v-add-sys-phpmailer and check what the error is

Probably nano /etc/php/7.4/cli/php.ini and disable the functions in the warning