Upgrade from D6 cause unability to edit existing node After upgrading my Drupal website from D6 to D7, I regularly get this error message that prevents me from being able to edit existing nodes:


  The website encountered an unexpected error. Please try again later.
  
  PDOException : SQLSTATE[HY000]: General error: 1366 Incorrect integer
  value: '' for column 'field_galerie_image_vdl_width' at row 1: INSERT
  INTO {field_data_field_galerie_image_vdl} (entity_type, entity_id,
  revision_id, bundle, delta, language, field_galerie_image_vdl_fid,
  field_galerie_image_vdl_alt, field_galerie_image_vdl_title,
  field_galerie_image_vdl_width, field_galerie_image_vdl_height) VALUES
  (:db_insert_placeholder_0, :db_insert_placeholder_1,
  :db_insert_placeholder_2, :db_insert_placeholder_3,
  :db_insert_placeholder_4, :db_insert_placeholder_5,
  :db_insert_placeholder_6, :db_insert_placeholder_7,
  :db_insert_placeholder_8, :db_insert_placeholder_9,
  :db_insert_placeholder_10), (:db_insert_placeholder_11,
  :db_insert_placeholder_12, :db_insert_placeholder_13,
  :db_insert_placeholder_14, :db_insert_placeholder_15,
  :db_insert_placeholder_16, :db_insert_placeholder_17,
  :db_insert_placeholder_18, :db_insert_placeholder_19,
  :db_insert_placeholder_20, :db_insert_placeholder_21),
  (:db_insert_placeholder_22, :db_insert_placeholder_23,
  :db_insert_placeholder_24, :db_insert_placeholder_25,
  :db_insert_placeholder_26, :db_insert_placeholder_27,
  :db_insert_placeholder_28, :db_insert_placeholder_29,
  :db_insert_placeholder_30, :db_insert_placeholder_31,
  :db_insert_placeholder_32), (:db_insert_placeholder_33,
  :db_insert_placeholder_34, :db_insert_placeholder_35,
  :db_insert_placeholder_36, :db_insert_placeholder_37,
  :db_insert_placeholder_38, :db_insert_placeholder_39,
  :db_insert_placeholder_40, :db_insert_placeholder_41,
  :db_insert_placeholder_42, :db_insert_placeholder_43); Array (
  [:db_insert_placeholder_0] => node [:db_insert_placeholder_1] => 97
  [:db_insert_placeholder_2] => 98 [:db_insert_placeholder_3] =>
  contenu_sortie_action [:db_insert_placeholder_4] => 0
  [:db_insert_placeholder_5] => und [:db_insert_placeholder_6] => 251
  [:db_insert_placeholder_7] => [:db_insert_placeholder_8] =>
  [:db_insert_placeholder_9] => [:db_insert_placeholder_10] =>
  [:db_insert_placeholder_11] => node [:db_insert_placeholder_12] => 97
  [:db_insert_placeholder_13] => 98 [:db_insert_placeholder_14] =>
  contenu_sortie_action [:db_insert_placeholder_15] => 1
  [:db_insert_placeholder_16] => und [:db_insert_placeholder_17] => 252
  [:db_insert_placeholder_18] => [:db_insert_placeholder_19] =>
  [:db_insert_placeholder_20] => [:db_insert_placeholder_21] =>
  [:db_insert_placeholder_22] => node [:db_insert_placeholder_23] => 97
  [:db_insert_placeholder_24] => 98 [:db_insert_placeholder_25] =>
  contenu_sortie_action [:db_insert_placeholder_26] => 2
  [:db_insert_placeholder_27] => und [:db_insert_placeholder_28] => 253
  [:db_insert_placeholder_29] => [:db_insert_placeholder_30] =>
  [:db_insert_placeholder_31] => [:db_insert_placeholder_32] =>
  [:db_insert_placeholder_33] => node [:db_insert_placeholder_34] => 97
  [:db_insert_placeholder_35] => 98 [:db_insert_placeholder_36] =>
  contenu_sortie_action [:db_insert_placeholder_37] => 3
  [:db_insert_placeholder_38] => und [:db_insert_placeholder_39] => 254
  [:db_insert_placeholder_40] => [:db_insert_placeholder_41] =>
  [:db_insert_placeholder_42] => [:db_insert_placeholder_43] => ) dans
  field_sql_storage_field_storage_write() (ligne 451 dans
  /var/www/drupal7/modules/field/modules/field_sql_storage/field_sql_storage.module).


What can I do to fix this? 

I also can't finalise my upgrade due to missing a widget in field type too - could these problems be linked?
If there was changes in the fields you were using in the very nodes, that renders nodes unusable, you will need to export data from 6.x site to some more or less universal format, like csv or xml, and import it anew to 7.x 


Delete migrated data and it's content type
Create new content type with new-style fields, that maps 1:1 to old node structure. If possible, keep names
Export node data from original site (recreated from backup if needed), using Node Export, Views data export or similar tool
Secure all the files referenced by nodes
If needed, manually upload secured files to new version; see next step
Import nodes using tool like Node Export or Feeds - it may be required for files to be already uploaded, read the manual of your importing tool