I am having this issue brought to my attention by people on IE but I cannot see it in Firefox.
They say it is in a popup which when they click OK they can then view the site as normal.
However the BIG issue is that as this appeared my site keeps turning off things in the server, or so it seems.
I am on VPS which keeps turning off so my server is not found.
WordPress with BP was also dragging down the normal server which is why I upgraded. But at present it has happened again and my server is turned off and I am waiting on them turning it on again.
Is this error linked? Does anyone know what it is and why it is happening?
Strange things happen like WP reCaptcha wont change settings, none of the spam settings work...
I just went on to delete a spam registration and the server vanished again.