Hi Rodica,
thanks for your response!
I made my own child theme, using these files:
archive.php
functions.php
sidebar.php
style.css
and also
/inc/template-tags.php
/template-parts/content-page.php
/template-parts/content-single.php
And yeah, the latest Hestia version worked for me without child theme, so I’m pretty sure the server error 500 is my own fault / caused by my small changes and additions into the original php files.
Regarding the missing font awesome icons:
The latest Hestia version doesn’t show them (even without child theme!), but 1.1.66 does. So there must be any changes in the Hestia core..
(I’ve got a crappy development site with latest Hestia, without child theme https://test.plejadium.de/. There should be icons in the primary menu, but they aren’t.)