ArtyomYabloko is right, that's not accepted because it's leaving out the translation of "sed".
As someone who has spent a long time trying to write all the translations that should be accepted in the last two days (and many other times on other courses), it's hard enough getting the literal ones, especially on the Latin side with that flexible word order I'm sorely tempted to use strong language about, without getting into anything non-literal, and when you start accepting those you end up with a problem of "Where do we stop?" Especially fun since there is a limit on the number of translations we can enter, which we don't hit often now but would if we accepted non-literal translations as well.
The placement test rejected a lot of my Latin answers because of word order. I know you heard that a lot and will continue to hear the complaint. I study Latin for 6 near 7 years now. Autem honeste possum intellegere cur laborem factam est dure. Nolite animum demittete! Et gratias do vobis quae fecerunt cursum hoc!
Yes, word order is a known issue, it's being worked on. It's just a slow process and then it takes a while for the answers we enter to actually be accepted for users, so many of the things users are reporting are actually already accepted in the Incubator, just not on the user-side yet. Don't assume that's the case, though, please keep reporting (with the button in the lesson, not in the sentence discussions)!
Think of it this way. The sentence is nonsensical (nobody's arguing that), but because of that, you're going to remember it and what "sed" means. The sentences about "I am a penguin" in other courses are also nonsensical, but again, they help you learn. Even if the sentence itself is ridiculous or nonsensical, it's giving you the building blocks to read and write sensible sentences, in a way you'll remember.