GetCurrentVolumePercentage seems to be the correct function name, so that is probably not it.
It seems to be the case that the path “/Script/” is wrong.
I don’t know what causes this, this is outside of my plugin’s control, there is nothing I can program or configure to change that.
My guess is that it’s either:
incorrect engine/project settings
a bug in UE4
a bug in the launcher
The best thing to do is to find out what is causing the errors, you can do this by asking yourself these questions:
what did I actually do with my project that resulted in this error?
what steps would someone have to take in order to get these errors as well?
With that it might become more obvious what is causing the errors.
You should probably also post it in the answerhub as a bug report as well, preferably with the answers to the two questions, since that will help whoever is reading your post quite a lot.