Layout is fine, it’s displayed just fine on our test PC.
I’d have only one advice - the duration on clock item, you might want to lower it a bit
Understanding Media Duration and how it affects the playback of a Layout
Just to confirm CMS is also 1.7.8?
mm, could you also please open php.ini, find this line
always_populate_raw_post_data -1 and make sure it’s not commented out (no ; before that line in php.ini)
After that, please restart your web server.
If that won’t fix it.
Could you turn on debugging (Report fault page) and auditing for your display (Displays page).
Then check logs page and see if there are any additional errors there.
You can also check recent log and media inventory of your display on Displays page.