When launching with both Flowing Background and the 'Slight' GUI Modifications mods installed, the game will fail to launch and a crash report will not be generated. The launcher will produce a popup announcing the crash with no further details.

The issue only occurs with Flowing Background 1.1.0, and downgrading to 1.0.0 allows me to launch with both mods.

Potentially important note - SGM's latest release at the time of writing, 0.4.0, seems to have its own crash on startup issue. To test this incompatibility, I'd recommend using SGM 0.3.0, which is able to launch without issue unless FB 1.1.0 is installed.

Any update on this issue? I have the same problem with the latest versions of both mods in 1.16.1

Could you post the full game log (logs/latest.log)? It should have info even if there's no crash report.

Oh, just noticed - looks like SGM 0.4.1 also crashes with FB 1.0.0, unlike SGM 0.3.0. This doesn't change anything with regards to compatibility between the most recent versions of both mods, but it does mean that my previous statement of "The issue only occurs with Flowing Background 1.1.0, and downgrading to 1.0.0 allows me to launch with both mods" is no longer accurate.

Sure thing! Here's the log from a failed launch. I've updated SGM to the latest release because the dev there fixed the issue that was making it necessary to use the older version, so I'm just launching with SGM 0.4.1 and FB 1.1.0.
latest.log

Ah, it's a problem with the title screen panorama replacement.