im on win7 64bit and i have the same problem as molly
it crashes and i cant take a screenshot because it doesnt allow me

it crashes as soon as i click a gradient from the list of the pop up menu

EDIT:
wait
it crashed like five times in a row, and suddenly it works
i didnt change anything

I have used all the functions of the last posted Iccii layer effects. No crashing in win7 64bit....none.

There were no errors. I replaced the old version where the sample two was under a Layers heading...which gave me two Layers headings...I was happy you changed that.
What I have been doing is....I can find the scripts I am thinking I need to remove and other parts in the folders for my gimp 2.8 portable version, and when I do...I take a snip shot of where they are...I take them out and put them on my desktop, then I restart gimp and see if it did what I hope for...if not, I put them back. I try to find everything by using a search for the main word of the process being used...to get everything out that goes with them. But, I think in this case it was just a matter of the .scm files...I do know... I messed with some that were layerfx too though...it got a little sticky...but all is good on my program.
I hope this helps in some way...sorry I can not say 'exactly' what I did.

Also, for anyone who might be interested to know...as it is working pretty good for me so far...I keep a copy of everything I have put into my gimp, plus everything I have taken out(in labeled folders, so I know what is what)...just in case I crash it.
I took the gap out of my 2.8(I know I got everything out, because I had a copy of everything that was put in), but I kept some of the extra .scm's that still worked...I went through them to make sure they still work for video and many still do. I have tested that and tested it and all is good...but I still could take more out OR put stuff back if I have to. I will keep my fingers crossed

I am running gap 2.6 on another 2.6 version of gimp and that works very well.

The Iccii I have is 3.4.13...I got it earlier today.

@ Graechan,

Yes thanks I downloaded it, just haven't installed it yet.

I'm using Gimp 2.6.11 and I have...

iccii-convolution-presets.scm
iccii-cross-light.scm
iccii-pastel-image.scm
iccii-soft-focus.scm
iccii-texturizer.scm
iccii-water-paint-effect.scm
iccii-wrap-effect.scm and now the new updated iccii-layer-effects.scm.

That's a whole lot of iccii's...