Board Thread:Technical Updates/@comment-957747-20180117003818/@comment-126761-20180117214427

The main targets for this fix were Safari 9 (on iOS) and older versions of Chrome (such as Chrome 40), though it probably fixed the behaviour on others as well.

However, it is very unlikely that we will work on significant fixes for very old browsers like Safari 6 or IE9. Very few people are on them now, thankfully - and we would strongly recommend people switch anyway, due to the general security risks of using them.