com.rsa.jsafe.JSAFE_PaddingException: Could not perform unpadding: invalid pad byte
The above exception is encountered during server startup. This happens when SerializedSystemIni.dat present under domain\your_domain\security folder is modified.
To troubleshoot this issue, we need to do the following.
Check if the Domain is in Production Mode or Development Mode.
If its in Development, take a backup of your config.xml first.
Then change the values of the following elements of config.xml to clear text
credential-encrypted (at 2 places) and node-manager-password-encrypted.
If you have a datasource configured, or a jms resource, make sure to change the encrypted values in those configurations file as well.
If its a Production domain, then change it to Development by changing the production mode to false in the startup script and manually remove the entry for the production mode in the config.xml.
If still your issue is not resolved, fell free to post a comment and I will try to help you out.