Vee Validate: SyntaxError: Invalid regular expression

I use regex for password validate:

required|min:8|max:20|regex:/^(?=(.?[a-z].?[A-Z])|(.?[a-z].?[0-9])|(.?[a-z].?[!@#$%^&()_+])|(.?[A-Z].?[0-9])|(.?[A-Z].?[!@#$%^&()+])|(.?[0-9].?[!@#$%^&*()+])).*$/

But browser show error message:

[Vue warn]: Error in callback for watcher "value": "SyntaxError: Invalid regular expression: 
//^(?=(.*?[a-z].*?[A-Z])/: Unterminated group"

Thanks for support