What type of error message? Something like:
"The namespace "Recovery_Analysis" is not defined in access or evaluation of 'Recovery_Analysis:Plate Name' , Recovery_Analysis:Plate Name"
Most likely you don't need to use namespaces (the part before your table name) and something like this would be enough
Names Default To Here(1);
dt = Open("C:\Program Files\SAS\JMPPRO\16\Samples\Data\Big Class.jmp");
Names Default To Here(1);
dt = Open("MY FILEPATH");
dt_split = dt << Split(
Split By(:Chemistry),
Split(:Concentration),
Group(:Well Id),
Output Table("Split table"),
Sort by Column Property
);
dt_split << Save("MY FILEPATH FOR SPLIT TABLE");
be careful to not overwrite your non-split table
-Jarmo