Bug memory leak ?

I have made a custom modpack with a lot of mod (150) and fastcraft on the curse voice lancheur and I enconter a strage bug.

Sometime when I play, at totaly random moment the game stop registering my action like when a server is going to crash, but it last forever I can't open chest, item dont drop when I break bloc but I can still manage my inventory.

Most of the time the modpack run well but the bug can occure at any time, worst when I try to leave by save and quit of the esc menu the game stuck at disconnecting local server so I have to force quit the game and finaly if i try to relanch the game without reboot the PC it open fine but if I open a world it trow me back at the opening screen and frezee.

somtime my RAM is also overloaded.

sorry for the bad english (I'm belgian)