here's the crash report: https://ghostbin.co/paste/23zsc/raw
It worked fine with 6.13.01. Here's my mod list: https://ghostbin.co/paste/hfe8q/raw

I'm having the same issues as you, more or less. Looking through my fml-client logs, every crash is related to the fluid registry, such as
[Client thread/ERROR] [FML/]: The fluid registry is corrupted. A fluid gregapi.fluid.FluidGT lubricant is not properly registered. The mod that registered this is broken
and
[Client thread/ERROR] [FML/]: The fluid registry is corrupted. A fluid gregapi.fluid.FluidGT kerosine is not properly registered. The mod that registered this is broken
Since version 6.14 also merges greg's official changes into it, I'm gonna guess something broke in the proccess.

Fixed in 6.14.01

Already taking look on it.

Can confirm, works for me.

It also works for me now.