This patch ensures WS initial placeholders are not hidden, so they can be viewed in WS preview.
===================================================================
--- typo3/cms/typo3/sysext/core/Classes/DataHandling/DataHandler.php
+++ typo3/cms/typo3/sysext/core/Classes/DataHandling/DataHandler.php
@@ -1294,3 +1294,7 @@
                             // Setting workspace - only so display of place holders can filter out those from other workspaces.
                             $newVersion_placeholderFieldArray['t3ver_wsid'] = $this->BE_USER->workspace;
+                            // The initial placeholder must not be hidden to make WS preview work. The offline version can still be hidden.
+                            if (isset($GLOBALS['TCA'][$table]['ctrl']['enablecolumns']['disabled'])) {
+                               $newVersion_placeholderFieldArray[$GLOBALS['TCA'][$table]['ctrl']['enablecolumns']['disabled']] = 0;
+                            }
                             $newVersion_placeholderFieldArray[$GLOBALS['TCA'][$table]['ctrl']['label']] = $this->getPlaceholderTitleForTableLabel($table);