During the maintenance period on Monday, 14 Oct 2024, all new projects will no longer create a container registry as part of the project area. Already existing projects will be unaffected at this time. Instead, users should utilize the official ORNL container registries at camden.ornl.gov (internal/moderate) and savannah.ornl.gov (external/low). Please see ORNL Today article for more info.
The multiple dataset input parameter apparently defaults to the most recent valid option in the current history. This is not only often not desired but it sometimes defaults to an input that isn't valid and prevents the tool from starting.
Marking the input as optional prevents this behavior.