Disable 32-bit plugins

OK, then. One last change before the next release?

I looked at catching the exception, but it turns out for 32-bit plug-ins, it's a very specific exception and we were the ones throwing it, so I just made the changes there.

I initially thought we still needed to throw the exception to prevent the caller from doing …something? But I can't see any reason for it, so I've commented it out.