Hi,
I checked for zip in phpinfo, found the following:
Apache Environment
=============
HTTP_ACCEPT_ENCODING gzip, deflate, br
HTTP Headers Information
================
Accept-Encoding gzip, deflate, br
PHP Variables
========
$_SERVER['HTTP_ACCEPT_ENCODING'] gzip, deflate, br
Module Authors
==========
Bzip2 Sterling Hughes
Zip Pierre-Alain Joye, Remi Collet
is that fine?
also here are the permissions on lib/tpl and lib/plugins and a ps -ef | grep -e apache -e http -e php
viswiki01:~/dokuwiki # ls -ltra
total 100
-rwxr-xr-x 1 wwwrun www 18092 Aug 23 2015 COPYING
drwxr-xr-x 8 wwwrun www 104 Nov 27 2015 lib
-rwxr-xr-x 1 wwwrun www 19374 Jul 14 2016 feed.php
-rwxr-xr-x 1 wwwrun www 306 Jul 14 2016 README
-rwxr-xr-x 1 wwwrun www 20700 May 26 2017 install.php
-rwxr-xr-x 1 wwwrun www 33 May 26 2017 VERSION
drwxr-xr-x 8 wwwrun www 141 Sep 19 2017 vendor
drwxr-xr-x 12 wwwrun www 236 Mar 28 2018 data
-rwxr-xr-x 1 wwwrun www 3673 Jan 18 09:22 doku.php
drwxr-xr-x 2 wwwrun www 142 Jan 18 09:25 bin
-rwxr-xr-x 1 root root 381 Feb 4 08:59 test.php
-rwxr-xr-x 1 wwwrun www 2097 Feb 4 09:06 index.php
drwxr-xr-x 7 wwwrun www 4096 Feb 4 09:10 inc
-rwxr-xr-x 1 wwwrun www 1868 Feb 4 09:49 .htaccess
-rwxr-xr-x 1 root root 32 Feb 11 07:02 phpinfo.php
drwxr-xr-x 8 wwwrun www 241 Feb 11 07:36 .
drwxr-xr-x 7 root root 131 Feb 12 13:40 ..
drwxr-xr-x 5 wwwrun www 4096 Feb 12 13:49 conf
viswiki01:~/dokuwiki # cd lib/
viswiki01:~/dokuwiki/lib # ls -ltra
total 16
-rwxr-xr-x 1 wwwrun www 241 Aug 23 2015 index.html
drwxr-xr-x 3 wwwrun www 4096 Nov 27 2015 scripts
drwxr-xr-x 8 wwwrun www 4096 Nov 27 2015 images
drwxr-xr-x 8 wwwrun www 104 Nov 27 2015 .
drwxr-xr-x 2 wwwrun www 205 May 26 2017 exe
drwxr-xr-x 2 wwwrun www 108 Aug 30 2017 styles
drwxr-xr-x 3 wwwrun www 39 Aug 30 2017 tpl
drwxr-xr-x 8 wwwrun www 241 Feb 11 07:36 ..
drwxr-xr-x 35 wwwrun www 4096 Feb 12 13:50 plugins
viswiki01:~/dokuwiki/lib # ls -ltra plugins/
total 44
-rwxr-xr-x 1 wwwrun www 4438 Aug 23 2015 syntax.php
-rwxr-xr-x 1 wwwrun www 244 Aug 23 2015 index.html
-rwxr-xr-x 1 wwwrun www 665 Aug 23 2015 action.php
drwxr-xr-x 6 wwwrun www 233 Nov 27 2015 wrap
drwxr-xr-x 2 wwwrun www 47 Nov 27 2015 safefnrecode
drwxr-xr-x 2 wwwrun www 47 Nov 27 2015 info
drwxr-xr-x 8 wwwrun www 104 Nov 27 2015 ..
drwxr-xr-x 6 wwwrun www 207 Jan 26 2016 gallery
drwxr-xr-x 3 wwwrun www 225 Jan 26 2016 vshare
drwxr-xr-x 7 wwwrun www 212 Jan 26 2016 tag
drwxr-xr-x 7 wwwrun www 255 Apr 21 2016 include
drwxr-xr-x 5 wwwrun www 221 Apr 26 2016 blog
-rwxr-xr-x 1 wwwrun www 3124 Jul 14 2016 remote.php
-rwxr-xr-x 1 wwwrun www 15450 Jul 14 2016 auth.php
drwxr-xr-x 10 wwwrun www 224 Jan 3 2017 move
drwxr-xr-x 3 wwwrun www 97 Feb 15 2017 color
drwxr-xr-x 4 wwwrun www 154 Mar 13 2017 loglog
drwxr-xr-x 4 wwwrun www 147 Apr 13 2017 csv
drwxr-xr-x 4 wwwrun www 104 Apr 13 2017 newpagetemplate
drwxr-xr-x 4 wwwrun www 123 May 26 2017 usermanager
drwxr-xr-x 3 wwwrun www 174 May 26 2017 styling
drwxr-xr-x 3 wwwrun www 75 May 26 2017 revert
drwxr-xr-x 3 wwwrun www 111 May 26 2017 popularity
drwxr-xr-x 5 wwwrun www 172 May 26 2017 extension
-rwxr-xr-x 1 wwwrun www 2571 May 26 2017 admin.php
drwxr-xr-x 5 wwwrun www 101 Aug 17 2017 forcessllogin
drwxr-xr-x 8 wwwrun www 272 Sep 7 2017 dw2pdf
drwxr-xr-x 5 wwwrun www 212 Oct 9 2017 hidden
drwxr-xr-x 7 wwwrun www 216 Oct 19 2017 bureaucracy
drwxr-xr-x 4 wwwrun www 179 Dec 22 2017 cloud
drwxr-xr-x 3 wwwrun www 135 Jan 16 2018 rdplink
drwxr-xr-x 5 wwwrun www 101 Jan 31 2018 authad
drwxr-xr-x 3 wwwrun www 57 Jan 31 2018 authplain
drwxr-xr-x 5 wwwrun www 122 Jan 31 2018 config
drwxr-xr-x 4 wwwrun www 106 Jan 31 2018 authchained
drwxr-xr-x 4 wwwrun www 127 Feb 8 2018 addnewpage
drwxr-xr-x 4 wwwrun www 135 Feb 8 2018 pagelist
drwxr-xr-x 4 wwwrun www 156 Mar 5 2018 acl
drwxr-xr-x 3 wwwrun www 159 Jan 24 23:43 upgrade
drwxr-xr-x 4 root root 140 Feb 12 13:50 temp
drwxr-xr-x 35 wwwrun www 4096 Feb 12 13:50 .
viswiki01:~/dokuwiki/lib # ls -ltra tpl/
total 4
-rwxr-xr-x 1 wwwrun www 2084 Aug 23 2015 index.php
drwxr-xr-x 8 wwwrun www 104 Nov 27 2015 ..
drwxr-xr-x 3 wwwrun www 39 Aug 30 2017 .
drwxr-xr-x 5 wwwrun www 204 Aug 30 2017 dokuwiki
viswiki01:~/dokuwiki/lib # ps -ef | grep -e apache -e http -e php
root 1678 1 0 Feb12 ? 00:00:02 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 1815 1678 0 Feb12 ? 00:00:01 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 1816 1678 0 Feb12 ? 00:00:01 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 1817 1678 0 Feb12 ? 00:00:00 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 1818 1678 0 Feb12 ? 00:00:01 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 1819 1678 0 Feb12 ? 00:00:02 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 2562 1678 0 Feb12 ? 00:00:01 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 2563 1678 0 Feb12 ? 00:00:00 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
wwwrun 2564 1678 0 Feb12 ? 00:00:00 /usr/sbin/httpd-prefork -DSYSCONFIG -DSSL -C PidFile /var/run/httpd.pid -C Include /etc/apache2/sysconfig.d//loadmodule.conf -C Include /etc/apache2/sysconfig.d//global.conf -f /etc/apache2/httpd.conf -c Include /etc/apache2/sysconfig.d//include.conf -DSYSTEMD -DFOREGROUND -k start
root 20515 19380 0 07:40 pts/0 00:00:00 grep --color=auto -e apache -e http -e php
getenforce doesn't exist on the system, so I guess no selinux?
###EDIT
oh right the logfiles
I checked those too, /var/log/apache2/error_log /var/log/apache2/ssl_request_log /var/log/apache2/access_log
no activity to see in these files when I get the http 500 error except the posting of the 500-page
###EDIT END
I'll try next to upgrade manually by copying the files to the server and upgrade dokuwiki this way to see if that resolves the issue.
I will however take a backup of the current dokuwiki-folder to recreate the issue if needed.
Thanks
Dominik