warning: Division by zero in .../wp-content/themes/lay/frontend/frontend.php on line 440

[ll]

I have an error message at the top of the page:
warning: Division by zero in .../wp-content/themes/lay/frontend/frontend.php on line 440
What can I do to fix that?

[arminunruh]

Hmm,
I think there must be a project that doesn't have a project thumbnail / featured image.

[ll]

This post is deleted!

[ll]

Thanks for your help!
The warning message has disappeared.