Security Update 2015-004 trashes Apple.com SSL Certificate on Mavericks
Yesterday I installed the Apple Security Update 2015-004 1.0 on a variety of systems. One of those an Mac Pro 2008 with OS X 10.9.5 Mavericks could afterwards not access Apple.com anymore e.g. this site https://discussions.apple.com !!!
Safari: Error invalid Certificate
iTunes 12.1.2 no access to the iTunes Store: Error invalid Certificate
App Store.app: does not do anything and doesn't display any error
I restored the whole machine from TimeMachine backup from a day earlier - everything fine...
Tried to install the Security Update 2015-004 one more time - same problem it trashes the Apple Certs !
ps: the same security Update worked on other Mavericks systems, e.g. on an iMac 27" Late 2013, iMac 27" mid 2014, MacBook Pro Retina, 15-inch, Early 2013, but not on the MacPro 2008 ?
What to do ?