>General warning!
>When you do a table modify,
>you can destroy the db structure or lost data.

Is the setting in regards to that is "Prevent saving changes that require table re-creation"? That is the only one I remember having changed. However, it does not say it has an impact on removing a field and blocking its removal if it has an index. In my case, it works. For another person, he has the warning and cannot proceed.