If I start a modpack from technic launcher, nothing happens

[Dia_Pig]

Hi, so I have the problem that I installed a few modpacks but as soon as theyre done and I click on play the launcher closes and instantly reopens to the same page. I've tried several solutions that were suggested in similar threads like this but none of them worked. Here's my log: https://paste.ubuntu.com/26477944/

[EvilOwl]

We do not support java 9.

Uninstall java 9 and install the latest 64 bit java 8.

[Dia_Pig]

Thanks!