We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.
Also, never use the editor. Did you never come across that mantra here on the forums? I myself am posting this at least once a day. NEVER USE THE EDITOR.
All game files (including the scenarios) are in easy to understand text format. You can easily find the "alliance = {" part and just delete it.