Well, for anyone that has recently installed Windows 7 64bit and installed Oblivion and the Construction Set, there is possibly one thing you must do before attempting to edit existing plugins. That is, you must create a new plugin and save it. After that, you will have no more issues with the Construction Set for saves to existing files.

I personally had this problem, and all it requires is one new plugin creation to properly associate the access levels for every plugin in the data folder to the CS. You would think the original installation options to associate existing .esp's etc would have been sufficient. If you have not had this issue, then good for you. This is for everyone who is having issues with Windows 7 and initial saves/edits.

Hope it helps. :liplick: