It might be ViewFile but wont make a blind bit of difference, they both call ShellExecute with the same arguments but OpenBrowser prepends the HTTP part if missing, this is the only difference (source code: WindowsCore.cpp
OpenBrowser Line 9462, ViewFile Line 9612)
Interestingly though, OpenBrowser does already contain the code to grab the browser path from the registry but its been commented out for some reason.
The reality is though, OpenBrowser is
View File: Opens the given file in an the external application suitable for its file type. Typically this is a default app chosen by the user.
OpenBrowser: Opens the default browser of the current platform and points it to the page given.
OpenBrowser is wrong, the commented code does what the help says, the current implementation is the same as ViewFile ie: opens the given file in an the external application suitable for its file type
if anything try it (both Open and View) but without the "file:///" part, the code checks for ":" and if not found will prepend "http://"