I tried to change the Linux account password from PAM UI but failed with below error message.
What is causing it?

Credentials -> Manage Targets -> Accounts -> Update an account password
PAM-CM-1349: A problem occurred while executing the script processor. Please try your request again or contact your Administrator.

Release:
Component: CAPAMX

This can be a common issue with Target Unix/Linux using Chinese/Japanese/Korean language.
There are 2 steps to resolve this issue.

Step1: Change the Target Application's "Script Processor" section "Change Password Command" to set environment variable "LANG=C" and then execute "passwd".

This forces the Change Password Prompt to appear in "ENGLISH" which the default expression would be compatible with.
Depending on the Unix/Linux OS, the command to set the environment variable and how to add additional command to run would be different.
Ensure the LANG environment variable is set in UPPER case.
It would be good to change all the commands to include the "LANG=C && <command>" for the rest of commands as shown above.

Step2: In case if the password still fails to update, configure the target account to change password using another account.

In case if the other account you are using is not "root", such as "admin", then you will need to select "Use the following account to change password" and "Verify using other account's credentials".