I think there is an issue with 2.0 version, on loading a save that already had the mod enabled i get the following error:
The mod Adaptive Movement Speed (0.4.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event adaptive_movement_speed::on_load()
adaptive_movement_speed/control.lua:101: attempt to index global 'global' (a nil value)
stack traceback:
adaptive_movement_speed/control.lua:101: in function 'register_on_tick_handler'
adaptive_movement_speed/control.lua:129: in function <adaptive_movement_speed/control.lua:128>

I did not get it on the start with the mod, only the second time.

Reproduction:
1. create save without mod
2. install mod
3. save with the mod
4. quit
5. start the save from step 3

Thanks for reporting, I missed a file in the upgrade, it should be fixed now!

Unfortunately it still doesn't work (

Error while running event adaptive_movement_speed::on_load()
adaptive_movement_speed/control.lua:101: bad argument #1 of 2 to 'next' (table expected, got nil)
stack traceback:
[C]: in function 'next'
adaptive_movement_speed/control.lua:101: in function 'register_on_tick_handler'
adaptive_movement_speed/control.lua:129: in function <adaptive_movement_speed/control.lua:128>

It resolved my issue, thanks!
@PressNT: maybe a silly question, but did you update to the latest version?

Yes, 0.4.1 adaptive_movement_speed_0.4.1

Unfortunately it still doesn't work (

How do you reproduce this issue? Did you perhaps have a save with adaptive_movement_speed 0.4.0 and then upgrade to 0.4.1?
Try disabling the mod, loading the save, re-saving, then enabling the mod again.

Try disabling the mod, loading the save, re-saving, then enabling the mod again.

Works! Thank you.