FormBuilder IFrame blocked by Firefox

[joe_ma]

Sorry for asking this question here, but I cannot ask it in the VIP section because I use an version of FormBuilder that is expired.

I have a fairly simple form on a website done with FormBuilder (PW 3.0.148, FormBuilder 0.2.4) that seems to work quite well. I've tested it with Firefox (88.0.1), Chrome, Opera, Edge and it works in all browsers as expected. The form is embedded in the page by pasting the name of the form in the body field.

Now my customer tells me, that her Firefox (88.0.1) is blocking the page where the form is embedded: "Firefox may not open this page" for safety reasons.

I have no clue as to what seems to be the problem here, since the form is on the same server and has the same domain.

[joe_ma]

Just so as you know: The problem was triggered by Kaspersky anti virus software. It seems to interfere with Firefox. Weird but still a problem for all of us, since the combination Firefox/Kaspersky might be rather common.