Note: This was originally posted by an inactive account. Content was preserved by moving under an admin account.
Originally posted by: Tim MeagherThis error can occur when a node requires either one parameter or another, however neither of the parameters are set.
For instance in the Excel File node, the node needs to either have no inputs, and have a "File" parameter specified, or needs to be connected with an input, and have the "FilenameExpr" parameter set.
If neither of these parameters are set, then the node can't know which Excel File(/s) to load, therefore it is an error.