If you get this error message in the NAV connector for the enumerated maps
[NAV Enumerated Values to Picklist] has encountered an error while processing key [Countries_Regions]. Sequence contains no matching element
This means you haven’t read the install documentation correctly (don’t ask how I know this!!) and you haven’t applied a hot fix.
Basically between version 1 and version 2 of the connector they added in a new map to the enumerated types, this was probably because I think the countries field used to cause problems when mapping, especially when a user would type in a massive long value.
You need to run through this hotfix
You basically add a few values to the integration code unit.