Fresh Ubuntu 20 install won't install mod-packs. Stuck at creating env, or installing vanilla launcher

[tjpoe]

Fresh install of Ubuntu. Download of ftb-app and run it, but trying to install any modpack, and I just get stuck at creating env, or installing vanilla launcher.

FTBA/launcher.log and FTBA/error.log here: logs

i've followed a few recommendations online to install libgconf-2-4, which i did, but it still doesn't work. also tried to remove and pre-create the .ftba and .ftba/bin directors. but no success.

the instance folder that gets created just has an image and an instance.json file in it. I've tried to remove the FTBA, .ftba and .config/ftb-app directories and re-install, but the same thing happens every time.

the .ftba directory includes a bin directory with a launcher_log.txt file in, which doesn't make sense to me, because it never gets to the minecraft launcher step.

the contents of that file show timestamps several hours in the future as well:

[Info: 2020-10-23 23:43:46.388087306: LauncherMain.cpp(84)] Initiated models
[Info: 2020-10-23 23:43:46.388167611: NetQueue.cpp(232)] NetQueue: Setting up.
[Info: 2020-10-23 23:43:46.388190922: LauncherMain.cpp(217)] Running launcher core (version 2.1.17785)
[Error: 2020-10-23 23:43:46.388530339: LauncherMain.cpp(222)] Failed to initialize network

 

[grandrolf]

Install and use java version 8

 

[tjpoe]

for anyone who finds this later, it seems like there are 2 issues. 1, the java v8 issues as noted by grandrolf, but also, the launcher needed libcurl4 to function as well. This was discovered after I manually copied a working instance into the directory and tried to run that. when I did that, I could see an error message about missing libcurl.

After installing libcurl, i was able to install my own instances, but the minecraft launcher would fail, until i installed java8.