A transparent signon Ideal transaction receives an Ideal error message like the following one just after it's started:
IDADCMDP02E - Command invalid or incomplete starting at "SC00T"
Actually, the invalid string can be any combination of characters, not only SC00T.
Among the possible causes:
Starting with Version 15.1, CA Ideal for CA Datacom searches the SCF User-Maintained Transactions (SCUMTRAN) table if SCF has not located an entry in SC00TRAN. See additional info on Ideal 15.1 manual here: SCF User-Maintained Transactions Table (SCUMTRAN)