Version

5.0.1

Browser and OS info

Chrome 73

Steps to reproduce

on the chrome, throw a error is "Uncaught TypeError: path.split is not a function" when I use "registerModule" to register a nested module. Here is my code:
this.$store.registerModule(['activity', 'detail'], module);
The position of error code and stack is here:

I think the reason of this error is because of setting "path" param with a error type,
it want to get a string, but set array with slice

What is expected?

set path with a correct type

What is actually happening?

set "path" param with array, but it want to get string