There has been indeed a problem in the packaging of this specific version. Could you grab
photoflow-w64-20170914-git-linear_gamma.zip and see if it works? I checked it and all seems to run fine.
Also, since the
linear_gamma branch will soon become the basis for new releases, I am very much interested in any feedback you could have.
FYI, I am planning to write a post describing what is new and different in this branch.