DanielPtr

Do you know for sure you pasted the snippet in your active functions.php file, that is, in the functions.php file of your current theme (or child theme)?
Check if you have the newest Woocommerce version (3.0.1).
Disable all your Woocommerce plugins and check if the mails will send now.
If not, disable all plugins and check.
Good luck ??!

Yes, I agree about the official acknowledgement. Maybe you could test the snippet with a test order, so you don’t have to wait?

I’m glad it helped. Credits for the original github poster.

I hope the Woocommerce developers will come soon with a more permanent fix.

It looks like the problems are because of the new deferring of order emails (for extra performance during the checkout). I’ve found this website with solution: https://github.com/woocommerce/woocommerce/issues/14151

In short, you have to add
add_filter( 'woocommerce_defer_transactional_emails', '__return_false' );
to the functions.php file of your WordPress theme. This removes the new function for deferring emails. For me, this was the solution.
Be sure you know what you are doing when you change your functions.php file!

Good luck.

• This reply was modified 7 years, 11 months ago by DanielPtr.

You are brilliant! That was indeed the cause of the error. I’ve installed another plugin for the logo, and no problems so far. Thanks!