Sorry, another necro. Ran into the same problem, documents fix didn't help. Ended up adding code to set file attributes normal prior to deletions.
private static bool Backup()
{
//custom
string backups_root = Path.Combine(Core.BaseDirectory, "Backups")...
Sorry to necro, had the same question as poster above but it wasn't here. Found it anyway :
per SkillCheck.cs its in PlayerCaps.cfg.
_AntiMacroCode = Config.Get("PlayerCaps.EnableAntiMacro", false);
FYI its off by default apparently...