Local installation - empty page after installation

I have just installed ConfTool on our server. When I call the page, it appears completely blank in the browser.
Do you have any hints as to what could be the problem?

There is probably an error in your conftool.conf.php file or your settings.php file.

Please follow the steps below:

• Double-check all your modifications in the ConfTool files.
• Enable the output of error messages in htdocs/settings.php.
• Have a look at the error log of the Apache web server (/var/log/apache/error.log).
• Test the output of info.php in htdocs.