In T160969#2260879, @SrgPuffy wrote:

So the Arma 3 - Other Profiles folder has to be on same disc as Arma? This doesnt explain it that well.

The hell! Just found a source of the problem on my side. The thing was that my documents folder was located not on the system disk and when I moved that folder back to C:\ it fixed everything. Hope my info will help you

Having the same issue, tried a lot of things and all of them didnt helped me at all.