No solution, just concurrency. I am attempting to upgrade from 2.3.0 and recieving the same error. I have gotten parse errors before (of course) but never on this particular line of this particular code. I'm reverting back to the last stable version right now, but would love to find out what the deal is.
2.3.1 brought problems for me too, after glitch free installs with prior versions. I was able to find the solution to my problems in the thread currently right below this one. Checkout Aram's fix, as it solved my problems.