Apparently I misconfigured something, but I have not idea what.

I'm playing with a fresh install of ProjeQtor 7.4.3. I created an example Ticket, added some notes, closed and reopened it some times, and then wanted to generate a PDF from it, but I only get server errors:

2019-03-25 12:48:48.169 ** ERROR ** [V7.4.3] ERROR **
2019-03-25 12:48:48.169 ** ERROR ** [V7.4.3] on file '/var/www/projeqtor/external/html2pdf/src/Html2Pdf.php' at line (1508)
2019-03-25 12:48:48.169 ** ERROR ***** [V7.4.3] cause = getimagesize(css/customIcons/grey/iconReply.png): failed to open stream: No such file or directory

Any hints what I might be doing wrong?

Regards,

Gunter