Heya,

Is this an issue you've seen yet?

https://forum.feed-the-beast.com/threads/fairy-lights-string-will-cause-client-to-crash-when-placed-in-world.211311/

Looks like a crash when placing certain fairy lights: http://paste.feed-the-beast.com/view/9c5e4ee9

Mod Version: 2.0.3
Forge: 2185

Thank you for checking this out :)
Darkosto

Thanks for the report, this is a duplicate of #7 and is fixed in 2.0.4