What kind of flaws exist in our current society?
We're the most technologically advanced culture that has ever existed; we have plenty of problems.
An advanced technocratic society would certainly make use of extensive automation, even if it's just using engines in place of human muscle. Not everybody has the skill set to fully engage in a technocratic society, so you're going to have a bunch of people unable to contribute effectively.
Power corrupts. It doesn't really matter what safeguards you put in place, if the powerful choose to ignore them, they can do so and get away with it. It could be as simple as a teacher favouring those students he happens to like and ignoring those he doesn't, or as blatant as engineering a race of subhuman slaves who can labour without any rights. Unless you have your ethical rules enforced by a computer that's totally disinterested in human foibles, they're always vulnerable to corruption.
Case in point - the constitution of Japan guarantees equality before the law, the right to due process, the right to a fair trial, etc, yet the Japanese justice system has an implausibly high 99% conviction rate. Simply being arrested is seen as evidence of guilt; proclaiming your innocence results in harsher punishments. The letter of the law is one thing, but human actions are another.
Depending how advanced you want your tech to be, you may have a society with advanced, sentient AIs. Those AIs, being essential to running certain equipment, must be shackled, controlled, and forced to obey - essentially, they must be enslaved.
This, of course, could result in subtle rebellions, with AIs rebelling by following the exact words of a human's order, and causing chaos from a slight imprecision in speech.
There's something of a trope in fiction of scientists being entirely focused on potential benefits and ignoring short-term damage. If the technologists discover a cure for cancer that requires the sacrifice of ten people for every hundred saved, they could well choose to start killing the 'less useful' at the bottom in order to save the rest. They could see this as a genuine good, since they're helping more people than they harm.
Strict social control
Humans aren't neat and orderly. Humans are messy. We're tough to quantify and predict, we don't often act rationally, and we stubbornly resist control. All this could throw off predictive models and upset the technocrats.
They might respond with social crackdowns, requiring people to fit into their models and patterns so that they can run things 'efficiently.
In the end, scientists are just as human as anyone else - and as much as they may wish to pretend otherwise, they're still subject to human failings.