(Job for apache2.service failed because the control process exited with error code) occured after trying to activate webdav module - linux

Question

I tried to start my apache webserver but I can't. Every time I type in:
sservice apache2 start
I get the Error:
Job for apache2.service failed because the control process exited with error code.
I got the error the first time after I tried to activate the WebDAV module for apache2. But I already deactivated it. I rebooted the server too but no effect.
I'm running the apache on my second pc and access it via SSH.
Heres my Logfile:
--
-- A start job for unit phpsessionclean.service has begun execution.
--
-- The job identifier is 1448.
Jul 28 18:39:31 Server-MS-7B28 systemd[1]: phpsessionclean.service: Succeeded.
-- Subject: Unit succeeded
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit phpsessionclean.service has successfully entered the 'dead' state.
Jul 28 18:39:31 Server-MS-7B28 systemd[1]: Finished Clean php session files.
-- Subject: A start job for unit phpsessionclean.service has finished successfully
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit phpsessionclean.service has finished successfully.
--
-- The job identifier is 1448.
Jul 28 18:40:25 Server-MS-7B28 sshd[2785]: Received disconnect from 222.186.31.166 port 58094:11: [preauth]
Jul 28 18:40:25 Server-MS-7B28 sshd[2785]: Disconnected from 222.186.31.166 port 58094 [preauth]
Jul 28 18:40:37 Server-MS-7B28 sshd[2787]: Received disconnect from 112.85.42.104 port 12119:11: [preauth]
Jul 28 18:40:37 Server-MS-7B28 sshd[2787]: Disconnected from 112.85.42.104 port 12119 [preauth]
Jul 28 18:41:43 Server-MS-7B28 sudo[2793]: pam_unix(sudo:auth): Couldn't open /etc/securetty: Datei oder Verzeichnis nicht gefunden
Jul 28 18:41:46 Server-MS-7B28 sudo[2793]: pam_unix(sudo:auth): Couldn't open /etc/securetty: Datei oder Verzeichnis nicht gefunden
Jul 28 18:41:46 Server-MS-7B28 sudo[2793]: elias-server : TTY=pts/0 ; PWD=/home/elias-server ; USER=root ; COMMAND=/bin/bash
Jul 28 18:41:46 Server-MS-7B28 sudo[2793]: pam_unix(sudo:session): session opened for user root by elias-server(uid=0)
Jul 28 18:41:53 Server-MS-7B28 audit[2808]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/usr/lib/snapd/snap-confine" pid=2808 comm="apparmor_parser"
Jul 28 18:41:53 Server-MS-7B28 audit[2808]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/usr/lib/snapd/snap-confine//mount-namespace-capture-helper" pid=28>
Jul 28 18:41:53 Server-MS-7B28 kernel: audit: type=1400 audit(1595954513.320:3245): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/usr/lib/snapd/snap-confine" pi>
Jul 28 18:41:53 Server-MS-7B28 kernel: audit: type=1400 audit(1595954513.320:3246): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/usr/lib/snapd/snap-confine//mo>
Jul 28 18:42:09 Server-MS-7B28 systemd[1]: Starting The Apache HTTP Server...
-- Subject: A start job for unit apache2.service has begun execution
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit apache2.service has begun execution.
--
-- The job identifier is 1515.
Jul 28 18:42:09 Server-MS-7B28 apachectl[2837]: AH00526: Syntax error on line 32 of /etc/apache2/sites-enabled/000-default.conf:
Jul 28 18:42:09 Server-MS-7B28 apachectl[2837]: Invalid command 'DAV', perhaps misspelled or defined by a module not included in the server configuration
Jul 28 18:42:09 Server-MS-7B28 apachectl[2817]: Action 'start' failed.
Jul 28 18:42:09 Server-MS-7B28 apachectl[2817]: The Apache error log may have more information.
Jul 28 18:42:09 Server-MS-7B28 systemd[1]: apache2.service: Control process exited, code=exited, status=1/FAILURE
-- Subject: Unit process exited
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- An ExecStart= process belonging to unit apache2.service has exited.
--
-- The process' exit code is 'exited' and its exit status is 1.
Jul 28 18:42:09 Server-MS-7B28 systemd[1]: apache2.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit apache2.service has entered the 'failed' state with result 'exit-code'.
Jul 28 18:42:09 Server-MS-7B28 systemd[1]: Failed to start The Apache HTTP Server.
-- Subject: A start job for unit apache2.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit apache2.service has finished with a failure.
--
-- The job identifier is 1515 and the job result is failed.
Thank you for your help,
Elias

Answer 1

The problem is because some configuration files are deleted, you have to reinstall it.
REINSTALL APACHE2:
To replace configuration files that have been deleted, without purging the package, you can do:
sudo apt-get -o DPkg::Options::="--force-confmiss" --reinstall install apache2
To fully remove the apache2 config files, you should:
sudo apt-get purge apache2
which will then let you reinstall it in the usual way with:
sudo apt-get install apache2

Answer 2

This can happen if port 80 is already under use.
refer the link for more
You can use this to check if something is using the port.
netstat -plant | grep 80