With MineFactory not installed, it seems that including a RedNet port in a reactor causes a crash and prevents loading of the save file until the block is edited out or MineFactory is installed. No dump, sorry, but this should be very easy to reproduce. I know there's no reason to use the port without MineFactory installed, but this seems like a pretty serious bug which could really frustrate someone unaware of the issue.

@erogenousbeef just need to make it so it requires said mod to be installed to make the block