Security msg RE: my ISP webmail site

Every time I use Firefox (44.01) to access my ISP's webmail page, I get a security warning that it is a dangerous site:

warning URL:

resource://c1a2a613-35f1-4fcf-b27f-2840527b6556/data/html/pagebadredirect.html

 

I have not clicked on any links on the page.  Is this for real or a bogus phishing attempt?  I notified redshift.com and they do not seem to care (no answer).   IT is annoying at best.  I am Windows 7, Firefox 44.01 (which I am really annoyed at for wiping my database of passwords with their 44.0 update), wireless on a hybrid secured network.

Not a crippling problem, just annoying.