My Hexxit on the Technic launcher loads properly, when the launcher is done loading Hexxit, it pops up the Hexxit thing and then it stays on a white screen and the Mojang sign doesn't even pop up. I've left it there for at least 2 hours+ while I was doing something else and when I got back, it was still on that white screen. It doesn't crash, it doesn't automatically pop off, it stays there as a white screen. I normally don't get any lag on any Technic modpacks and I have around 2g left on my computer to use. Is it that Hexxit is a very big modpack and takes a lot of space because I have a lot of junk I can trash but this is seriously abnormal. Can someone help me?
I had this exact problem. For me it was my texture pack crashing the game because it used too much RAM, however this can happen even if you don't use a texture pack. The way to fix it is to assign more RAM to the modpacks. On the technic launcher, click the cog icon in the top right corner, and use the drop down menu to assign more RAM to the modpacks.
I'm not sure of your circumstances, but I had the same problem on a Mac, and it ended up being because of a java version issue. There is a similar problem posted here that provided me a solution that worked. You can also show the console in the options and it will give you a more detailed report on why things aren't working.
Had the same problem and just figured this out. In the logs it will say it it can't open a particular file. Navigate to the files location as noted in the log, then rename the file that you find to the name the log appears to be missing.
So liblwjgl.jnilib becomes liblwjgl64.dylib when you attempt to launch again it will automaticaly generate a new liblwjgl.jnilib, but it will also keep liblwjgl64.dylib and it should launch correctly.
Hope this works for you : )
Edit: if you don't know how to open the log just go to the top right of the launcher and click the gear, there will be an option to enable it.