I get tons of messages of this style in my console log:
08.12.14 11:03:41,045 VMware Fusion Start Menu: assertion failed: 14B25: libxpc.dylib + 40320 [9437C02E-A07B-38C8-91CB-299FAA63083D]: 0x13
The effect started after updating OS X from Mavericks to Yosemite. Updating to Yosemite 10.10.1 did not help.
I have installed VMWare Fusion 6.05 which should be compatible to Yosemite and the effect happens also when Fusion is NOT running.
The problem is hard to investigate as the string appears in many posted logs that discuss other topics.