post your logfile from the help menu. make sure that Razer Synapse is not installed as I've heard it can cause issues with OBS.
other ones that can cause issues are raptr (for AMD GPU) nvidia experience nVidia GPU), Overwolf, Steam in-home streaming and broadcasting.
I typically tell people to uninstall if you dont use these or disable the feature that could be causing a conflict.
Lastly, from what I hear window capture is what you want H1Z1 set to for the current time. I am unsure of the setting to use but remove any game capture for H1Z1 from sources