Rocket won't stage even when staging unlocked

[isdi0]

Hi, I've been trying to make a KSP Cinematic, and I built a space shuttle for this purpose, and for some reason, in the editor the stages are all fine, but when I go to launch it, the staging all combines into one single stage. Additionally, the stage light is off, but I still can't stage, even after fixing the staging. My mod list is here, I have no idea what's causing the problem, but I really don't want to uninstall and reinstall every mod one by one to find the problem, as it would take ages to do so. In addition, I have a _patches folder with one single patch, aptly named engine_startup.cfg, it's a very simple script which makes engines have a realistic warmup process. Also, I have a couple of manually installed mods, the only ones I used on this craft are reDIRECT and SOCK, along with SOCKrecolored and SOCKrepainted. I'm pretty sure it's a problem with the craft, as other craft work perfectly fine, I launched a small test rocket, it worked fine.

KSP.log file

Edit: So I figured out the source of the problem, it's Modular Launch Pads. I have no idea how MLP is causing this problem, but it is.

Edited August 19, 2022 by isdi0
found source of problem

[isdi0]

OK, so I think I might or might not have tracked it down to one error:

[ERR 12:22:05.812] [AssemblyLoader] Exception when getting assembly attributes: Exception of type 'System.Reflection.ReflectionTypeLoadException' was thrown.

Additional information about this exception:

 System.TypeLoadException: Could not load type of field 'MuMech.MathJ.Utils:DoublePool' (1) due to: Could not load file or assembly 'System.Buffers, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. assembly:System.Buffers, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51 type:<unknown type> member:(null) signature:<none>

Before that, there's also this error:

[ERR 12:22:05.521] [ERROR] [Part benjee10.shuttle.forwardFuselage] [ModuleB9PartSwitch 'name'] Cannot reassign cube weights: had 6 cubes before but now have 12

Does anyone know what either of these mean?