Support for Nitrogen is discontinued. The word on the street is that the author has gone on to work on other projects. Since the mod is currently several versions behind the stable release, and is known to cause issues, you are advised against using it.
Originally posted by westernwilson: Oops. OK is there a way to go into the save file and get my forge and materials back? or insert a fictional one? I really don't want to have to go out and find all the mats again.There isn't really a way to do that. But, you could enable creative mode and spawn in the approximate amount of missing materials.
F1 to open the console, type in "cm" without the quotes and hit enter, then exit the console by hitting F1 again, and hit the U key- Should bring up a menu full of items which has a search bar at the top. Spawn whatever you need to, then exit creative when you're done.
Note that this will only work in SP or on a server in which you are an admin.