Your character will then be updated to the Terraria version that you used to load the character with. A character will not be permanently blocked by the Editor, you just have to know what the problem is with your character (which usually ends up being an unsupported item or an unsupported character version).
Any blocking the Editor does is merely temporary due to your character having an item or a version that isn't supported and thus, cannot handle, and can almost (99.9% of the time) always be fixed. A mod that provides you with a variety of bags and holders to store your items.
I've yet to run into a permanent 'block' by the Editor on any character I have created. #Terraria 1.3.4.4 inventory editor update.
