Tiki is not properly set up:
The directory '/var/www/localhost/htdocs/tikiwiki/temp/templates_c/' is not writeable by apache.
1- With FTP access:
a) Change the permissions (chmod) of the directories to 777.
b) Create any missing directories
c) Execute the Tiki installer again (Once you have executed these commands, this message will disappear!)
2- With shell (SSH) access, you can run the command below.
a) Run setup.sh and follow the instructions:
$ cd /var/www/localhost/htdocs/tikiwiki
$ sh setup.sh
The script will offer you options depending on your server configuration.
b) Execute the Tiki installer again (Once you have executed these commands, this message will disappear!)
If you have problems accessing a directory, check the open_basedir entry in
/etc/php/apache2-php7.4/php.ini or httpd.conf.
Consult the tiki.org installation guide if you need more help or visit the forums