The Flash: 10 most disliked episodes, ranked
3. "A New World Part Three: Changes" (season 9, episode 12)
The CW released just one promo still for this episode prior to its airing, as if they knew it was going to be received so poorly so they decided to gaslight us all into watching it by keeping that a secret. That one promo still was of The Flash, which means they knew exactly why people were tuning into a show called The Flash. That's also pretty funny in hindsight, because this episode is about anything but The Flash.
This is the penultimate episode of the series and yet its main character barely features in it. Instead, we have an episode all about Cecile, who time travels to 2049. As mind-numbing as that sounds, it could have been pretty cool if... everyone didn't look exactly the same. It's true; while audiences had many gripes with this episode, the biggest was probably the baffling decision to have everyone look exactly the same 26 years later... including Cecile, who would have been in her '70s. But no, she's donning a super suit for the first time ever and calling herself Virtue.
Again, this is the second last episode of The Flash ever. And instead of focusing on Barry Allen and/or Iris West, we have more meaningless moments spent on characters like Cecile, Khione, and Chillblaine. After "A New World, Part One" opened the final arc strong, hopes were high, but each installment after that got considerably worse. And even though the final installment was a heck of a lot better than this one, it was all a colossal disappointment at the hands of creatives who failed to understand the beauty of the show they inherited.