ah that might be good news then to get to the bottom of this issue.
Do you mind visiting https://www.microsoft.com/en-us/download/details.aspx?id=48145 → choose Download, ensure in the following dialog you choose vc_redist.x64.exe → click Next and the download should start.
Once done, if you run it and install it fully, might need to restart your system. That missing file should be there now and try the SAFE Browser then please to run it and see if you can create an account.
Side note: That download link is to install some dependencies(Visual C++ Redistributable 2015) required in the system which are not part of the browser application itself but expected to be installed in the target system. An installer should be performing a similar check to what you did and doing the install step if required, but this package not being an installer isn’t currently doing that check and it just might be that which is causing this issue cos of the missing dependencies.