Better... I think is the hard but definitive way.
Pasting until you find the conflictive bookmark and fix or remove it.
As I said, I don't know of any tool.
The worst has happened to me with bookmarks is that, suddenly, bookmarks file becomes empty. If that day is a lucky one, you can recover from the auto-backup file, or some recent backup, but is a pain anyway.
Hope you find the conflicting bookmarks