Replace the bracketed [...] placeholders with your own information.

URL(s) where the issue occurs

http://www.triglav.si/zavarovanja/posamezniki/zavarovanja_na_potovanjih/zdravstveno-zavarovanje-na-potovanjih-v-tujini-z-asistenco/zdravstveno-zavarovanje-na-potovanjih-v-tujini-z-asistenco

Describe the issue

1. Open the above URL
2. Middle click the red button with text "Sklenite zavarovanje - popust do 20 %" that leads to https://skleni.triglav.si/isklepanje/zdravstveno/

Expected result: The link should open in new tab
Actual result: The link opens in a new tab AND the current window is closed. To the user it looks like the link was opened in the same tab and tab history deleted, because the back button is disabled (no history).

Screenshot(s)

No screenshots.

Versions

• Browser/version: Firefox Nightly 58.0a1 (2017-10-12) (64-bit)
• uBlock Origin version: uBlock Origin 1.14.14

Settings

• None

Notes

• If I turn uBlock Origin off, the behaviour is as expected.
• I have noted this unwanted behaviour with middle click on other sites, too.