"It is not possible to work with this colleague."

Translation: S touhle kolegyní není možné pracovat.

[Plat_]

"S tímto kolegou nelze pracovat." should also be accepted.

[VladaFu]

I will add "nelze".

[zeibura]

Colleague can be masculine or feminine, it should accept "s tímhle kolegou" as well.

[VladaFu]

And, what a surprise, it is accepted.

If some particular sentence was not accepted, you really have to report the complete sentence. Duolingo has the "My answer should be accepted" feature for this very purpose.

[TomasRejda]

" S tímto kolegou se nedá spolupracovat" Is that a possible alternative translation. I realize that the given translation is more precise but: "not possible" can be translated with "se nedá" and "work with" can be "spolupracovat"..?

[AgnusOinas]

Yes, your sentence is absolutely fine. The problem here is that we're currently accepting over 2.500 possible versions of this sentence, and that's still not covering all possibilities. :D

But yes, "is not possible" can be "není možné", "je nemožné", "nelze", "nejde" or "nedá se" - the last two are more casual, but dictionaries still list them as standard.

And "spolupracovat" is good and accepted.