33454.188 Error MainLoop.cpp:1429: Exception at tick 9098410: The mod Fluid level indicator (0.9.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Fluid-level-indicator::on_tick (ID 0)
Fluid amount has to be positive.
stack traceback:
[C]: in function 'get_fluid_count'
Fluid-level-indicator/fli/fli.lua:104: in function 'fli_update'
Fluid-level-indicator/fli/fli.lua:232: in function <Fluid-level-indicator/fli/fli.lua:228>
33454.191 Error ServerMultiplayerManager.cpp:84: MultiplayerManager failed: "The mod Fluid level indicator (0.9.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Fluid-level-indicator::on_tick (ID 0)
Fluid amount has to be positive.
stack traceback:
[C]: in function 'get_fluid_count'
Fluid-level-indicator/fli/fli.lua:104: in function 'fli_update'
Fluid-level-indicator/fli/fli.lua:232: in function <Fluid-level-indicator/fli/fli.lua:228>"
33454.191 Info ServerMultiplayerManager.cpp:803: updateTick(9098410) changing state from(InGame) to(Failed)
33454.192 Quitting: multiplayer error.
33463.512 Info ServerMultiplayerManager.cpp:146: Quitting multiplayer connection.

Thanks for the report, I am having trouble reproducing the error, please tell me more about your setup where it's happening.
Are you mixing fluids? Which factorio version are you using? (2.0.10?)

I can reproduce this with the current configuration:
https://ibb.co/2g9XwYz

When the Heavy Oil get empty (reaching 0 on the marked Indicator), the server crash with the Report from above. We can reproduce this also in another base, with the same configuration.

Thank you! I am working on this now.

Thanks for your patience, I could not reproduce the error but I have changed something, which hopefully fixes it. Please update to version 0.9.3 and let me know if you still have the error.

Tested it and it did not crash! Tyvm :)