Describe the issue
A fresh install of Do a Barrel Roll and Flashback crashes. Disabling one or the other fixes the issue.

Crash report/logs (if applicable)
https://pastebin.com/xcrxMVMm

Additional information
The window opens for a bit but the Mojang titlescreen was never rendered. Window opens and immediately closes, unlike any other crashes I've encountered

I have no idea what I changed, but it works now. Flashback up, Do a Barrel Roll up, it worked. It seems like it only works if a few more mods are up. I remember deleting some mods except for Do a Barrel Roll and its dependency, CICADA, then Flashback and Sodium. Then I reinstalled most of the mods I deleted, and I guess it works now. Here's a log of the session.

https://pastebin.com/ruaxJECY

So, I'll close the issue for now. I'll try deleting some mods again, and if it ever breaks, I'll reopen.