After upgrading my Ubuntu Server to 18.04 my Dokuwiki failed to start properly.
After searching the web for ages, I finally found the Problem.
Thought I`d share the fix here in case someone else has the same Problem.
This is what some use wrote : -
For some reason libapache2-mod-php did not install correctly. Purging it and reinstalling it fixed the Problem
Found hier
http://aptosid.com/index.php?name=PNphpBB2&file=viewtopic&t=2967
To get my Wiki working again all I had to do was log onto my Server and Input these lines into the consol
sudo apt-get purge libapache2-mod-php
sudo apt-get install libapache2-mod-php
After that my Wiki worked the way it was meant to :-)
Hope this helps others