Launcher not opening modpacks

[JokeInABox]

Hi All,

when i install a modpack and click play, all it dose is close launcher then minecraft appears in the taskbar takes a few seconds then switches to the name of the mod im trying to play (Legands) then dose nothing, wont let me click on it and when i hover over its just a blank white box. 

I have tried a Couple of different things to get it to work but to no avail.

Reinstalled minecraft and launcher

restart PC 

Changed to 64bit java and set to 4GB ram 

checked to see if my NVIDA was up to date 

 

all help would be greatly appreciated.

link to my logs https://pastebin.com/rNEDnvKb 

[FabulousPotatoes]

I'm having a similar problem, but it's not completely the same. I was having problems opening the modpacks, so I installed the 64-bit Java, and uninstalled 32-bit. When I tried to change the memory, it only went up to 1GB. Did I do something wrong? I restarted my device and everything.