Oracle Solution for Error ora-32021

ORA-32021: parameter value longer than string characters

What triggered the Error:

An attempt was made to alter a parameter value but the number of characters in the parameter value was longer than the allowed maximum. For a list parameter, one of the values in the list was longer than the allowed maximum.

What should we do to fix it:

Reduce the parameter value length and retry the command. For the DISPATCHERS parameter, use listener aliases to reduce value length.