Alexandre,
I think we need a bit more info on how you are creating the string/string list in the first place. A rule of thumb in cases like this is to ensure that the initial mapping to an object enforces it to be a string list [and never just a string].
You can use services like appendToStringList in WmPublic/list to help you out in this case. So, as you map your data to the intermediate structure, always use appendToStringList. This way, even if you only have one string, it will be a string list.
If this doesn’t help, if you have any more details of the early steps of your mapping [ie. what structure is the data, how you map it now etc] send it across.
James…
#webMethods#Integration-Server-and-ESB#webMethods-General