To answer your question, I don't think there is a fix at this point. The only real option (that I know of at this point) is to find ways to live with or avoid the spellbook crash (by reducing the need to open spellbooks) .
I can tell you what I've been doing to minimize the number of times I get the spellbook crash.
It seems like it happens less often or maybe it doesn't happen immediately after if I do the "Perform full file check" when I start the EC back up after the spellbook crash. It may just be coincidence or maybe the full file check helps. I only do the full file check after the spellbook crash and I don't do it every time, but it has seemed to help when I do it.
For me, it seems to crash more often when I open a spellbook and drag a spell icon to a hotbar. I don't usually get the crash if I just open a spellbook to look at something and then close it. (Once again it may just be coincidence).
My approach to avoid the crash has been to make multiple hotbars and place all of the spells I use in the hot bars (or macros) so I can avoid opening a spellbook as much as possible. I realize this is not necessarily the best option but at least it helps to avoid the crash.
Since I play on Siege mostly now days and my chr has mutlipl spellbook based skills that I change in and out depending on what I am doing that day, I have a lot of hot bars with most of the spells. If you have more than one chr, once you get a hotbar set up on one chr, you can copy the hotbar from the chr setup file to a different chr's setup file to help avoid having the make the same hotbar for a different chr. (doesn't matter if the hot bar setup comes from a chr on a different shard).
I usually copy the entire chr setup file and just update the chr number and container number in the setup file. This way my entire desktop setup can be copied from one chr to another in the EC. There are a few things you still have to fix by doing it this way, but I find it easier than setting a chr up from scratch.
I'm not sure if any of this helps you, but I thought I would pass this info along just in case.
Starcon of Siege