Views Table format unusable

A view that lists entities built by ECK has broken table format.

When setting the Display Format to Table, the settings form shows "Broken/missing handler" everywhere.
The Fields configuration section of the View also shows "Broken/missing handler" and form content shows:

The handler for this item is broken or missing. The following details are available:

table: paciente_subforms_field_data
field: title
id: title
exclude: