Guide for JIRA Admistrators gadget shows error "limit of 0 users that are allowed to log in to JIRA"

The Guide for JIRA Administrators gadget shows "a problem" when the number of active users is the same as the number of users allowed by the license

JIRA 6.4:

It appears there is a problem with your current license. It specifies a limit of 0 users that are allowed to log in to JIRA. Please verify you have got the correct license key on My Account"

This message was different in prior versions:

JIRA 6.3.15:

You have reached the number of users allowed to use JIRA by your license.
If you require more user accounts, consider purchasing a full license.

This has been reproduced with 10 and 25 user licenses.