Here is a phrasing of some Cartan Theorem B statements: > Consider the following conditions: > > 1. $X$ is a {Stein manifold, affine scheme, coherent analytic subvariety of $\mathbb{R}^n$, contractible subset of $\mathbb{R}^n$}. > 2. $\mathcal{F}$ is a {coherent, quasi-coherent, coherent, locally constant} sheaf (of $\mathcal{O}_X$-modules) on $X$. > 3. The sheaf cohomology $\operatorname{H}^p(X,\mathcal{F})$ is zero for $p\geqslant1$. > > Then (1) + (2) $\implies$ (3). Here this statement applies to four geometric contexts: {complex-analytic, complex-algebraic, real-analytic, smooth}. In all of these, a "sharpness" statement also holds: > Given arbitrary $X$, if every sheaf $\mathcal{F}$ (of $\mathcal{O}_X$-modules) that satisfies (2) also satisfies (3), then $X$ satisfies (1). (For the two complex contexts, this is "classical"; for the real-analytic case, I believe this should be covered in Cartan's paper "[Variétés analytiques réelles et variétés analytiques complexes](http://www.numdam.org/article/BSMF_1957__85__77_0.pdf)" but I should check this; for the smooth case, this is [quasi-folklore](https://math.stackexchange.com/questions/717018/cohomological-whitehead-theorem)). **Question.** *For the four contexts above, is the remaining implication known to be true? i.e. is the statement* > Let $X$ satisfy (1); if an arbitrary sheaf $\mathcal{F}$ (of $\mathcal{O}_X$-modules) satisfies (3) then it satisfies (2). *true?* I assume this should be false, at least in the smooth case, given the existence of e.g. injective sheaves that are not locally constant, and I think in the complex-algebraic case it's also false ([thanks to skyscraper sheaves](https://math.stackexchange.com/questions/642262/is-skyscraper-sheaf-quasi-coherent)) but I'm not so sure about the other cases. Ideally an answer would consist of four "yes/no" answers with some references, but I'd be happier with some partial answers than with no answers at all :-)