Q Everything seems to be working fine since upgrading OS X, apart from a single website: Safari keeps reporting a runtime error when I try to connect to it. Is this a known issue?
A Broken sites after any major system or Safari update may be the result of using an old version of Java.
In the days when Apple distributed Java for OS X, we could visit Apple’s support site and download the latest release of Java appropriate to the current release of OS X. Now we have to go to the main Oracle Java page and obtain the installer package from there.
Once installed you may find that the site works fine again.
If it does not, you should enable the Develop menu in Safari, and use its tools to get a better idea as to what it wrong or missing. To do this, open Safari’s Preferences, and select the Advanced tool. At the foot of the window, select ‘Show Develop menu in menu bar’. You can then access several valuable commands to work out what is wrong: Safari’s error console may give much more detail of the error encountered, you can set Safari to pose as a different ‘user agent’, and most valuable of all, you can view the page source. If you can read HTML, the latter will give you the best clues of all as to where the problem lies.
Updated from the original, which was first published in MacUser volume 30 issue 1, 2014.