When about to merge a pullrequest, bitbucket attempted to render the diffs, however, it breaks and reloads in an infinite loop. This may be related to this line of the code:
<!-- <script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> -->
as this was the only change in the pullrequest. So it's impossible to merge.
Workaround: just remove the line instead of commenting it out. I verily believe the <!-- broke your rendering of diff and thus created an infinite loop. Hope this helps.