just in case, we figured this out...
the reason is that according to documentation it had to be sent such as "Parameters.param , etc...
our parameter's name was "PID" and it expected an integer value of 1.
this was changed to only
app.open(
"TIBCO Spotfire Example Files/StoreSales/StoreSales",
"webPlayer",
'PID = 1; ApplyBookmark(bookmarkName = "All");');
and this resolved the issue :)