Hi Stefania,
Thanks for reaching out to us! Hopefully I can help you with this one 🙂
First of all I would like to make sure this if this is caused by WooTickets, by the snippet or by a combination of both. So can you try to remove the snippet and then try to access the preview of posts and pages? If it still doesn’t work please deactivate WooTickets extension and re-test.
It’s also worth trying the steps described in our Testing for conflicts guide. This way we can see if this is a problem in our plugin or a conflict with the theme or other installed plugins.
Regarding the “Include events in main blog loop” issue, Can you please open up a new topic for it? That way it can be addressed by another team member simultaneously by another team member.
Please let me know about the test results,
Best,
Nico