Crash-report and latest.log are provided below:

https://hastebin.com/yowirapara.java
https://hastebin.com/nafewubili.md

And this screenshot shows the mods that have been installed after the last successful launch.

https://imgur.com/a/yrJjO5T

So probably it is not directly caused by Flux Network itself, maybe by incompability with some other mods. But it can't be figured out only by this report.

Appreciate your help.