Your system has run out of application memory ...
I'm long time Mac user w/mid 2012 MB Pro, 16 GB RAM, larger HD. My system was running quite well until I recently did the auto upgrade in Mavericks (10.9.5). Immediately following the upgrade the system more or less stalled noting that "Your system has run out of application memory", placing the active applications on pause and dramatically slowing down the system. Ever since that it has not worked which is a major crisis for me and my work. I have tried to restart, which helps the system for about 10 minutes (but still slower), reboot in security mode, plus read all posts I can find about the issue (which are many but with many very different suggestions). I, however cannot see that Apple has addressed this issue. I´ve tried to upgrade to Yosemite but system halts. Please help!!! Are there someone with needed insight for a definite fix for this issue?
MacBook Pro (13-inch Mid 2012), OS X Mavericks (10.9.5), 16 GB RAM, about 120 GB on main HD