The probe has to be sent full indeed.
By the way, apart from the probe tanks, I noticed that two of your fuel tanks are not full, one is even filled at only 65% of its capacity. In this case it's better to simply remove some fuel tanks. Remember that the empty tank has a mass too, which is 10% of the full mass. Removing some fuel alleviates the launcher, but the tank itself still has its full mass!
That trick is useful when you're slightly above the mass limit. For example if your launcher weighs 266 tons, you can remove a ton of fuel, because this is still the best choice, as the smallest fuel tank weighs 5 tons. Removing a 5 tons fuel tank would be less interesting in this case. But this is only for small adjustments.
However your launcher has been clearly built with efficiency in mind, so it shouldn't be too complicated to make some adjustments.
By the way, this is not related, but I noticed that the stats "Thrust", "Thrust/Weight" and "Part count" all showed 17.2t. This is most likely a bug. Do you know which mod it comes from? It could be interesting to report it.