I’ve disabled the plugin and all seems well now. I’ve checked on other sites I use and the Network error is coming up with the plugin enabled and not coming when it’s disabled.
Once you’ve used the plugin for a conversion, it is not needed anymore, so it is 100% reasonable and preferable to disable it.
But there is indeed a little bug. You must have some kind of diagnostic enable, or something that is monitoring internal files as normally trying to load an unavailable .js file is simply ignored.
I will post an updated version of the plugin before long.