Reserved characters in WebSphere Application Server passwords… Really!?

Had somewhat of a surprise today when IBM Support informed us that the issue our customer was experiencing could be due to unsupported characters in the password of the user mapped to the connectionsAdmin J2C alias. Say what!? But apparently there are restrictions on the different characters one can use. The password we were using had exclamation point (!) in it which is a no no. The customer is currently on WebSphere Application Server and support suggested we try and upgrade to Funny thing is that the customer has been using that password for years so it must have worked previously.

IBM Connections wiki: Special characters in password

WebSphere Application Server 8.5.5 InfoCenter: Characters that are valid for user IDs and passwords