Unfortunately, dependency lines are not exported to printed view, nor to PDF export.

Reason is that these graphic objects are displayed as Divs on the Gantt chart (using jsGantt javascript livrary).
In most cases, these divs just don't print.
This issue also occured to all the data in the Gantt chart (using and abusing of divs).
So, to get a printable view, new "report" has been developed, using simple tables.
That's why presentation slightly differs from screen view to print view, and representation of line could not be reproduced.

It is a limitation of a full web application, without any plugin.

Hint :
To get a printable view of Gantt planning, fully with lines, just get a smart screen capture tool, such as Lightscreen (free) or SnagIt : you'll be able to capture part of your screen and paste it in your favorite document editor.

Thank you for your quick response. I tried manually inserting the dependency lines (div's) into the iframe generated when clicking "print the planning" button. The dependency lines showed up within the iframe and it also prints fine when clicking "send document to printer" button. I'm wondering if it's possible to also draw dependency lines when "print the planning"?

It can, I think. :huh:
But it is some hard work. :sick:
All the calculation done in javascript on /view/js/jsgant.js from div based planning must be transposed in PHP on /tool/jsonPlanning.php to a table based planning. :silly:
Moreover, It needs to be Browser independant (multi browser compatible)... :whistle:
And the behaviour in the PDF export, using the same result, must also be checked. :whistle:
If you wish to do it, I'll be glad to insert it in a next version.
On my side, I will not try unless I get so free weeks off ... and a lot of coffee. 😉