The global properties page (Go to administration => Advanced Settings) of the GP doesn't specify that the user should not include any spaces in between the ID's, we should be able to accept spaces and remove them in the background with out rather displaying a non user friendly error as
An error has occurred!
The following error happened somewhere on this page:
javax.servlet.jsp.JspException: javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.el.ELException: Cannot convert 5089 of type class java.lang.String to class java.lang.Integer
(The full error stack trace output is in the source of this page.)