This started to happen right after the update.

The mod Rampant, fixed (1.10.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event RampantFixed::on_init()
RampantFixed/Upgrade.lua:1017: bad argument #1 of 2 to 'pairs' (table expected, got nil)
stack traceback:
[C]: in function 'pairs'
RampantFixed/Upgrade.lua:1017: in function 'attempt'
RampantFixed/control.lua:1775: in function 'onConfigChanged'
RampantFixed/control.lua:1830: in function <RampantFixed/control.lua:1827>

Me too. Not sure what other info to give at this point. Maybe I will start unchecking the other mods to see what happens.

Ok, unchecked all mods AND started a strictly default Freeplay world....crashed. I guess there is an incompatibility with the base mod? 8-)

BTW, my Factorio version is 1.1.109 build 62320 win64 and put all mod settings to default.

Rolling back to 1.10.2 fixed it for me.

1.10.3 is definitively broken :( Failed under any condition to start the gameplay (the game starts up to the menu)

You are right.
Fixed, now a new game is created without errors

Thank you! I confirm last fix worked :D