GroupWise 2014 R2
SSL is required when the monitor agent is run.
If a certificate is not configured, an in-memory certificate is generated when the monitor agent starts.
Newer versions of the browsers are starting to complain about that certificate.
(In the case of the attachment, it was Chrome 61.0.3163.100 (64-bit).)
To get around the problem, you can supply a valid certificate.
You could also use a utility, like openssl, to generate a self-signed certificate.
This issue has been fixed in an FTF build for both GroupWise 2014 R2 and GroupWise 18. Please open a service request and ask for the build that is appropriate to you system.