VGN0031W Function 'function-name' found, but DbfhFuncDB2 not installed. Default column type defined for 'field-name'

The named function exists in the datastore database, but cannot be accessed because DbfhFuncsDB2.dll/.so is not installed on the database server.
Resolution:
DbfhFuncsDB2.dll/.so needs to be installed on the database server (typically copied to the sqllib\function (Windows), or sqllib/function (Linux) folder).
Destination:
Console and standard error.