I got this when starting:

===
2.089 Custom mipmaps uploaded (99)
2.103 Factorio initialised
2.105 Mods to disable:Failed to load mods: bad argument #9 of 9 to '?' (string expected, got nil)
stack traceback:
[C]: in ?

Mods to be disabled:
• 3d-renderer (1.0.1)
38.793 Info AppManager.cpp:1422: Restarting Factorio
===

Hello! Thanks for the report. Must be some interaction with a mod. Could you provide a mod list or log file?

The log file is here: https://forums.factorio.com/viewtopic.php?f=190&t=113486

Don't see anything immediatelly obvious. Would have to try reproduce it myself. Could you provide a save-file?

Sure, same link to forum topic as before.
Save file is without this mod, since Factorio will not start with it.

I get the same error, disabling https://mods.factorio.com/mod/Fluid-level-indicator seems to work for me. I have tons of other mods loaded.

I do not have the glasses, but holy cow it sure looks like it is working... incredible!

Edit: Oops, I spoke too soon.
I do get the console message: 'Warning: Failed initializing sprites to mock a 3D world. Maybe try uninstalling the conflicting mod: 3D Renderer.'
But it seems to be rendering everything in 3D.

Maybe the warning is generated due to this:
21.173 Warning! Sprite at {0,0; 24x24} from flow-config/graphics/icons/tool-key-x24.png is defined with 2 mipmap levels, but level 1 is expected to be at {24,0; 12x12} which is out of bounds of the source image.
21.173 Warning! Sprite at {0,0; 32x32} from flow-config/graphics/icons/tool-key-x32.png is defined with 2 mipmap levels, but level 1 is expected to be at {32,0; 16x16} which is out of bounds of the source image.
21.173 Warning! Sprite at {0,0; 64x64} from flow-config/graphics/icons/tool-key.png is defined with 4 mipmap levels, but level 1 is expected to be at {64,0; 32x32} which is out of bounds of the source image.
21.191 Warning! Sprite at {0,0; 64x64} from mining-patch-planner/graphics/no-entity-zero.png is defined with 3 mipmap levels, but level 2 is expected to be at {96,0; 16x16} which is out of bounds of the source image.

Edit 2: I disabled Flow Config and Mining Patch Planner, but still get the sprites Warning on the console. The log file looks clean.

I got the same error even when only loading this mod and nothing else so I assuemd this must be on my end. There's a hidden setting that can build a texture atlas so the game loads very fast the next time you boot it up. After deleting that atlas file (..\AppData\Roaming\Factorio\atlas-cache.dat) the game loaded with all mods.

Just performed the update and saw a lot of debug info in the log file, so I put it here:
https://forums.factorio.com/viewtopic.php?p=610453#p610453

With The Fluid Level Indicator mod enabled:

3.065 Error ModManager.cpp:1625: Failed to load mod "3d-renderer": bad argument #9 of 9 to '?' (string expected, got nil)
stack traceback:
[C]: in ?
3.066 Loading mod core 0.0.0 (data.lua)
3.133 Checksum for core: 3215923532
3.176 Error ModManager.cpp:1625: Error in assignID: recipe-category with name 'crafting' does not exist.

Source: default (utility-sprites).
3.261 Initial atlas bitmap size is 16384
3.261 Created atlas bitmap 2048x800 [icon, not-compressed, mipmap, linear-minification, linear-magnification, linear-mip-level]
3.264 Texture processor created (2048). GPU accelerated compression Supported: yes, Enabled: yes/yes. Test passed. YCoCgDXT PSNR: 36.09, BC3 PSNR: 33.82
3.288 Parallel Sprite Loader initialized (threads: 5)
3.357 Sprites loaded
3.365 Generated mipmaps (5) for atlas [0] of size 2048x800
3.365 Custom mipmaps uploaded (99)
3.370 Factorio initialised
3.373 Mods to disable:Failed to load mods: bad argument #9 of 9 to '?' (string expected, got nil)
stack traceback:
[C]: in ?

Edit: After the update, now after a bit of time, I see:
[3D Renderer] [Info] If you are experiencing difficulties please consult the changelog for any breaking changes.
[3D Renderer][Info] Anaglyph renderings are not always perfect. Maybe try a different pair of sunglasses.
[3D Renderer][Warning] Extra processing has determined that factorio might work better in 2D.
[3D Renderer] [Warning] If you are experiencing nausea. dizziness or Satisfactory-driven visions, please stop using this 3D Renderer mod.
[3D Renderer][Error] This mod is not to be taken too seriously, No real math was performed to really make it work. Should have been released on April Fools I guess.
[3D Renderer][Info] Honestly, even if Factorio was available 3D I would still stay with 2D.

Egad! Got me.

This should be fixed in the latest release :)

Confirmed, the loading issue with Fluid Level Indicator active has been resolved.

Fixed indeed. Thanks for the quick response!

I get the same error, disabling https://mods.factorio.com/mod/Fluid-level-indicator seems to work for me. I have tons of other mods loaded.

This was super helpful though, thanks for the information!