This is a common issue with repacks. Try running the installer in Compatibility Mode for Windows 7 or as an Administrator Missing .dll Errors:
Because there is no official PC version of Uncharted 4 (until the official remaster on modern systems), the "RG Mechanics" release you are referring to is likely a "pseudo-port" or an emulated version. rgmechanicsuncharted4athiefsend2015 verified
Idle, Walking, Running, Jumping