I have had this problem since the first time I installed the emfield module - and then it seems to fix itself and break again all on its own. It's maddening.
Basically, if you install the module, add video fields to a node type, make sure all permissions are correct, and add a video (let's say from YouTube for example) - the video node is created and works fine.
However, when I then try to build a view which includes this field, that's when the trouble starts. The field may appear in the field drop down list, and you can add it just fine. However, when you save the view, the line where the video field and options were listed then turns blank - the field is still given a line, but all text descriptions and options are blank (they are gone). At this point, the page to see the View gives an error along the lines of:
"user warning: Unknown column 'node_data_field_ext_video.field_ext_video_embed' in 'field list' query: pager_query SELECT DISTINCT(node.nid), node.changed AS node_changed_changed, node.title AS node_title, node.changed AS node_changed, node_data_field_ext_video.field_ext_video_embed AS node_data_field_ext_video_field_ext_video_embed FROM drpl_node node LEFT JOIN drpl_term_node term_node ON node.nid = term_node.nid LEFT JOIN drpl_term_hierarchy term_hierarchy ON term_node.tid = term_hierarchy.tid WHERE (node.type IN ('video_ext')) AND (node.status = '1') AND (term_node.tid = '53') GROUP BY node.nid, node_changed_changed ORDER BY node_changed_changed DESC LIMIT 0, 16 in \includes\database.mysqli.inc on line 151."

If I delete the field from the list, even though it's blank, and then clear the site's cache, you can then pull up the View page, but of course the video field isn't pulled - which is sort of the point.

Does anyone out there have any advice on this? I've been fighting this for months and months. Every time I think I have it beat, or think it's a conflict with another module (removing the other modules) - it pops up again.

It's driving me BONKERS.

I'm on Drupal 5.7, emfield 5.x-1.2, Views 5.x-1.6 and CCK 5.x-1.7

Thanks,
-Michael