Link to pdf on wiki only opens in new tab or new window but not in same tab.

[HarryBroeders]

I can only open a link to a pdf document by right clicking the link and select open in new tab or open in new window. When I just left click the link a waiting circle keeps spinning forever. For example if I click the first link on the wiki page https://bitbucket.org/HR_ELEKTRO/rts10/wiki/LEGv7 the browser send a GET command to https://bitbucket.org/HR_ELEKTRO/rts10/wiki/LEGv7/LEGv7-Pinky_ebook.pdf?iframe=true&spa=0 which results in a NS_BINDING_ABORTED error.