Hi,
I know I might be late - if you want HTTPS then define it in SMICM and export the PSE and import in your browser - this error will not be there but https will be https:
As the certificate is not validated against certi authority.
However if you don't want HTTPS switch - go to that service in SICF
Double click the service >> Error Pages >> Configuration >> in Action During Logon >> Protocol
Choose Logon via HTTPS or Do not Switch
Do mind to update either you want this Globally or Service specific...
Should not as now for switch!! It will be in HTTP maybe..
Cheers,
TD