Can't create fields in existing content types. Get an error stating the field type is inactive when it isn't.

Hi there,

I was wondering if someone could help me. From Googling the error itself I noticed a bunch of people experiencing the same issues but unfortunately none of the posted results have helped...

What I did - Went into an existing content type (export attached) and tried to create a new field. In this case:
Label: Metric
field_metric
Text
Text field

When I go to save the field I get two status messages and one error.

Messages:
Added field Metric.
Metric (field_metric) is an inactive Text field that uses a Text field widget.

Error:
This content type has inactive fields. Inactive fields are not included in lists of available fields until their modules are enabled.

I'm then unable to configure/remove this newly created field. I also can't move the field around in the UI.
If I try configure the field, the Label is now missing and the widget seems to have reverted itself to the first in the list (Select). If I 'Change basic information', the Field name is blank (and uneditable) and the Label is also blank. The field type is set to 'Date' and the 'Widget type' is 'Select list'.
If I try remove the field, I get the confirmation removal message but clicking the 'Remove' button does nothing.

The strangest thing is that it works fine on my local. On the staging server it has these issues.

What fixes I have tried:

• Disabled all CCK-related modules and then re-enabled them
• Disabled all CCK-related modules, left the main 'content' module enabled. Ran update.php. Re-enabled all CCK-related modules
• Transferred my database content from local to staging (having cleared the cache from the source beforehand)
• Cleared the cache (generally did this after any of the above)

What I have checked:

• In table 'content_node_field' my field 'field_metric' is set to 1 for 'active'
• In table 'content_node_field_instance' my field 'field_metric' is set to 1 for 'widget_active'

There have been no updates to the module since the site was first built (April 2011).

I couldn't possibly give an entire list of all the modules on this site as that would take forever, however I have a feeling that caching (and in particular memcache) may have something to do with the issue... It is the one thing that is on the staging server and not on local (which would explain how an identical database [and code base] would work on one instance but not the other). I also have the Boost module enabled and configured (but this is also set up on local).

The CCK enabled modules I have are: Content, Content Copy, Email, Fieldgroup, FileField, ImageField, Node Reference, Number, Option Widgets, Text, User Reference

If you require any further information then please don't hesitate to ask - I apologise in advance if this is not enough to go on.

I have also attached an export of my content type if that helps (AFTER the rogue field was added)... Thanks in advance to anyone who can help me out!

Cheers,

Marc