My library doesn't work anymore

Hi. First time poster here.

I use PI3 for about two years and I've developed... well, changed several effects to own versions, like changing the water emitter to a Phaser beam.

When I now try to open the library it says "Error: Access violation at 0x00421F88 (tried to read from 0x3858B068), program terminated"

Any way to repair the library? There's two years worth of work in there...

Thank you.

Alex