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:
1) Ideal transparent signon not defined in SC00TRAN;
2) The in-core copy of the Ideal member related to the failing transaction (i.e. the one defined in TRNDATA parameter of the SC00TRAN entry for that transaction) has been overwritten or corrupted (storage violation);
1) Check if SC00TRAN/USRTRANS members of Ideal CAVQMAC/CAVQSAMP libraries contain an entry for the transparent signon transaction;
2) Reload the in-core copy of the Ideal member related to the transaction via a DISPLAY MEMBER command of the member itself (or EDIT without changing anything);
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.