SK doesn't work with 64-bits Java 8 VM

Is there a reason for this? The 32-bits version of the latest Java 8 virtual machine seems to work without a problem.

it'd help if you told us how you access spiral knights (browser? standalone? steam-based?) and maybe some basic technical information. for now, from what little i have to go off of this is likely a problem on your end, as i was able to update from JRE 7 to the most recent version of JRE 8 without issue. i also know of several others who have updated to JRE 8/JDK 8 and have no issues launching SK
meep had a good point with relocating this to technical issues, but i'd also recommend sending in a support ticket as well if you feel that it's urgent enough to warrant it

I mean, I don't need per se the 64-bits version to play the game, but it was the one I usually liked to use just for the sake of "hacker-y".
So I guess it was just a general technical question since I can run the game with the default VM or the 32-bits version of the latest 8.31 JRE.
I'm running the game through steam, by changing the "java_vm" folder to the one with the JRE I want to test. The issue here is that the game doesn't launch if I put it the 64-bits 8.31 JRE. The java process keeps running on the background but it doesn't manage to launch the game, not even the black screen blink that usually happens before getting the full login screen.
Edit: for the record, I'm not completely sure about which version of the 64-bits JRE stopped working for me. Last time I updated my PC was around 2 months ago and I remember facing this problem for the first time with the most recent JRE version at that time, which I resolved by reverting back to the default SK's 32-bits JRE. Today I updated my PC again and tried with the current 64-bits JRE, but it's still not working. I wonder what could be the problem, hmmm.

~$ java -version
java version "1.8.0_31"
Java(TM) SE Runtime Environment (build 1.8.0_31-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.31-b07, mixed mode)

Mines been running on 1.7.0 64-bit for awhile now. Maybe it's time to update it.
Again, as noted before - this thread belongs in the tech support subforum.
Move this page to Technical Issues, they should be able to help you there. Otherwise, call support via: https://www.spiralknights.com/support/#mail if you have a big issue with it.
Otherwise, if this is just a general technical question, never mind.