Long story short, if you use the Dusk Stone Hoe to turn yourself invisible, and then attempt to open a PC (both with the command as well as using the PC item) it causes a "fatal error has occured, The connection has been terminated" report and crash.

Cannot reproduce. If you have any other mods installed with your setup please list them and grab the crash report you spoke of and paste it here: http://pastebin.com and give us the link so we can look into this.