-- One constraint on Cache: it must always include a properly saved 'errors'
  -- element (created further down in this function).

  -- errors are not persisted, and stored in Cache['errors']
  Cache['errors'] = {id='errors', filename=Directory..'errors', left=0, right=Display_settings.column_width, lines={}, line_cache={}}

  -- a read-only buffer for errors
  Error_log = {id='errors', filename=Directory..'errors', left=0, right=Display_settings.column_width, lines={}, line_cache={}}

  table.insert(Cache['errors'].lines, {mode='text', data=err})
  table.insert(Cache['errors'].line_cache, {})

  table.insert(Error_log.lines, {mode='text', data=err})
  table.insert(Error_log.line_cache, {})

  cache_errors = Cache['errors']

  Cache['errors'] = cache_errors