Ariane 5 didn't lift off gently from the pad like so many other large rockets in recent memory. It bolted like a sprinter. It almost sprang. I don't think I've ever seen such a large rocket leave the pad so quickly.
CRUD = Contamination Resulting in Undesirable Deposits.
CRAPP = Contamination Resulting in Additional Partial Pressure.
Change your vacuum pump oil now.
Test. Testing, 1,2,3.