Cannot read property 'wrapping' of undefined

[ajoslin103]

More and more frequently I am getting this error:
(using 0.5.7)

grunt output:

Running "htmlangular:files" (htmlangular) task
Fatal error: Cannot read property 'wrapping' of undefined

my config:

    htmlangular: {
      options: {
        tmplext: 'html',
        customtags: [
          'action-icon-set',
          'hovering-frame',
          'editing-frame',
          'osk-keys',
          'd3-chart',
          'd3-chart-line',
          'icon-menu'
        ],
        customattrs: [
          'datatable',
          'dt-options',
          'dt-columns',
          'dt-instance',
          'stop-event',
          'dropzone-config',
          'event-handlers'
        ],
        relaxerror: [
          'Element “form” does not need a “role',
          'The “for” attribute of the “label',
          'An “img” element must have an “alt',
          'Bad value “{',
          'The element “label” must not appear as a descendant of the “label” element',
          'Unclosed element “label”',
          'End tag “div” seen, but there were open elements'
        ]
      },
      files: {
        src: ['<%= yeoman.app %>/views/*.html', '<%= yeoman.app %>/tmpl/*.html']
      }
    },

[dkatzberg]

I had the same error. You get this error, if you validate too often / too much. You should visit https://validator.w3.org/ after the error happens. You should get the information "Forbidden due to abuse. Access to this resource is denied due to abuse from your IP address.". ;) The problems should solve by itself after 24 h.