Hello, everyone.

I sometimes encountered WrongModeException when editing Activities, using Property-Set method or StringBuffer-Append method in Pega 7.3.1.

The message displayed is as following:
"com.pega.pegarules.pub.clipboard.WrongModeException: The property RH_1.pySteps(2).pyStepsCallParams.pyStepsParamUI was of mode String while com.pega.pegarules.data.internal.clipboard.ClipboardPropertyImpl.iterator() was expecting a List or Page mode. Details: (none)"

At first, I thought that something wrong occured with the parameter type of Property-Set or StringBuffer-Append.
However, when I look at the Clipboard, the parameters of Property-Set and StringBuffer-Append are stored in RH_1.pySteps(n).pyParamArray(m), not RH_1.pySteps(n).pyStepsCallParams.pyStepsParamUI.

(For other methods (such as Property-Map-DecisionTable, Log-Message, and so on), the parameters were stored in RH_1.pySteps (n) .pyStepsCallParams.pyStepsParamUI.)

Can anyone help me to clarify the following points ?
* Why does the program which raised the Exception check elements other than where the parameters are stored with Property-Set and StringBuffer-Append ?
* How can I avoid this Exception ?

Thanks in advance.