Try opening the project in the 32bit version of FL, and see if it crashes there. If it doesn't crash, try enabling bridged mode in the plugins advanced options to see if it forces FL64 to bridge it. This is assuming that the native loader is crashing. Otherwise, remove it from the project in FL32, save, then in FL64 load the 32bit version if it exists. Hopefully one of those will work.

I love how the kick and clap turned out on this one. It says better mix because it's the second, better, and shorter version.

Aerithos - Pyxis Nautica (Better Mix)

A quick question on Sidechain -

Does anyone ever use multiband sidechain compression? In this particular instance, I'm looking to duck only the Sub from my Bass bus but not the higher frequencies. I was playing with Trackspacer for this purpose.

Would be interested to see what other techniques people use.

What I recommended previously, Volume Shaper 4, will do this perfectly. It's a 3 band volume envelope processor with MIDI triggering.

I've found using MIDI triggered Volume Shaper 4 gives incredible control as a sidechain. You can really do some cool suppression type response (like in Flume's remix of Lay Me Down), or separate the release for the upper and lower frequency bands to allow most of the instrument to come through immediately after the attack while the tail of the kick dominates the <100hz range for it's full length.