An unhandled exception of type 'Microsoft.SharePoint.SPException' occurred in Microsoft.SharePoint.dll

Additional information: One or more field types are not installed properly. Go to the list settings page to delete these fields.

If your getting this exception you may be incorrectly referring to fields that have a space or other special character in them. WSS encodes some characters using a _x0000_ format where the green zeros are the Unicode code point in hex of the character, left padded to four zeros. For example if you had a field called "Default Location" you would call it by its "encoded" version "Default_x0020_Location" where _x0020_ represents the space. You can also learn the underlying name of the field by using the Solution Generator and viewing the list definition: