🇬🇧United Kingdom @andyrigby

We've just experienced this issue, but it was reproducible each time on a particular Paragraph "Remove" button.

The node edit form was large; lots of paragraphs, fields, meta tags, schema.org metatags etc.

The issue was the _triggering_element_name was not present in the POST variables, even though it was sent by the browser.

We needed to increase the max_input_vars php setting from 1000 to 1200 (in our case)

This resolved it for us.

andyrigby → created an issue.

Incase anyone has a similar issue, this was causing a WSOD when the devel module was enabled.

Disabling devel allowed me to see the error and find this issue.