Not sure if many others still playing Craft Of The Titans but there is a bug with the NuclearCraft Infinite Water Source which crashes out the game whenever you have the block placed.
The crash log can be found here - https://pastebin.com/WeA5YSpK.
@Boolyman, is there any chance of you having a look at this please? As it would be nice for me to continue using my 1.29 world on 1.30 with the block placed.
In reply to JesterCorex:
I also have had this problem several times with the same block. I've had to restart the entire game multiple times because of it, since I cant figure out how to reload previous saves... lol