New technology nodes "has unresearched reqs" in existing saves.

[paul23]

Well I wish to extend the research tree - and use it in my old save file. Now I added a simple node (to test):

 

    RDNode
    {
        id = shapedFuelSystems
        title = Shaped Fuel Systems
        description = Fuel tanks don't have to cylindrical.
        cost = 100
        hideEmpty = False
        nodeName = node4_shapedFuelSystems
        anyToUnlock = True
        icon = RDicon_fuelSystems
        pos = -1652,1412,-1
        scale = 0.6
        Parent
        {
            parentID = fuelSystems
            lineFrom = RIGHT
            lineTo = LEFT
        }
    }

 

Which shows up nicely, and works good, at least in a new game for testing.

If I try to load an old save file where I wish to use it, it errors out. The node shows up nicely, however it states: "Technology has unresearched requirements", even though I already researched "fuelSystems" in the file. How can I fix this? - I run kerbal construction timer with quite an unforgiving timing on researching so I prefer not to edit my save file and delete "fuel systems" research node. (Or should I delete it, and load ksp, then add the node to the researched list again?)