Hello,
I don't understand what does the words "blow up" mean? Because I am a chinese. I ever used the Shipping.ByTotal plugin. It works well. Below is the steps for using the plugin.
Copy the Shipping.ByTotal folder which lies in the compiled folder to the plugin folder.
Admin Tool -> Configuration -> Plugins -> Install
Admin Tool -> Configuration -> Shipping -> Shipping rate computation methods, Select the IsActive for ByTotal.
Admin Tool -> Configuration -> Shipping -> Shipping Methods, Add some methods
Admin Tool -> Configuration -> Shipping -> Shipping rate computation methods, Configure ByTotal.
Additionally, I add a State/Province support for shipping charge adjustment.
I hope it can help you!