Why does Connect fail to write a value in my Global Picklist?

Resolution

If this picklist was created using a Global Value Set in Salesforce, you will need to re-synchronize your picklist field from that Global Value Set in Salesforce. As described in this Salesforce question, to re-synchronize your picklist field you must edit the record type and assign the picklist values in the Global Value Set to the field. Once your picklist field has been re-synchronized, you can retry writing those records to Salesforce.