Error while running event factory_solver::factory-solver-toggle-main-window (ID 213)
factory_solver/ui/common.lua:79: attempt to index field '?' (a nil value)
stack traceback:
factory_solver/ui/common.lua:79: in function 'open_gui'
factory_solver/control.lua:115: in function 'toggle_main_window'
factory_solver/control.lua:128: in function <factory_solver/control.lua:127>

happening everytime i try to open the ui

Fixed crash when adding this mod to an existing save in version 0.1.1. Try to see if your problem has been resolved.

now it opens up!
but pressed the machine preset button and it crashed again

The mod Factory solver based on IPMs for LP (0.1.1) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event factory_solver::on_gui_click (ID 1)
Unknown sprite "capsule/yumako-mash"
stack traceback:
[C]: in function 'add'
flib/gui.lua:65: in function 'add'
flib/gui.lua:105: in function 'add'
flib/gui.lua:105: in function 'add'
factory_solver/fs_util.lua:93: in function 'add_gui'
factory_solver/ui/machine_presets.lua:71: in function 'handler'
flib/gui.lua:177: in function 'dispatch'
factory_solver/fs_util.lua:145: in function 'dispatch_to_subtree'
factory_solver/fs_util.lua:98: in function 'add_gui'
factory_solver/ui/common.lua:114: in function 'open_gui'
factory_solver/ui/common_settings.lua:38: in function 'handler'
flib/gui.lua:177: in function <flib/gui.lua:160>

Fixed in version 0.1.2.

hmm :P
when trying to add new

The mod Factory solver based on IPMs for LP (0.1.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event factory_solver::on_gui_click (ID 1)
factory_solver/ui/constraint_adder.lua:66: attempt to index field '?' (a nil value)
stack traceback:
factory_solver/ui/constraint_adder.lua:66: in function 'handler'
flib/gui.lua:177: in function 'dispatch'
factory_solver/fs_util.lua:145: in function 'dispatch_to_subtree'
factory_solver/fs_util.lua:98: in function 'add_gui'
factory_solver/ui/common.lua:114: in function 'open_gui'
factory_solver/ui/solution_selector.lua:32: in function 'handler'
flib/gui.lua:177: in function <flib/gui.lua:160>

The migration code did not seem to be correct. Fixed in version 0.1.4.

new crash :/
added in plastic and when i tried to add in coal to that production line i got this

The mod Factory solver based on IPMs for LP (0.1.4) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event factory_solver::on_gui_click (ID 1)
factory_solver/manage/info.lua:513: assertion failed!
stack traceback:
[C]: in function 'assert'
factory_solver/manage/info.lua:513: in function 'typed_name_to_craft'
factory_solver/manage/save.lua:218: in function 'get_fuel_preset'
factory_solver/manage/save.lua:518: in function 'new_production_line'
factory_solver/ui/production_line_adder.lua:164: in function 'handler'
flib/gui.lua:177: in function <flib/gui.lua:160>

The code was vulnerable to mod configuration changes, so all were inspected. Fixed in version 0.1.5.

Hopefully no more crashes will happen...

sorry to say this but i got this
The mod Factory solver based on IPMs for LP (0.1.5) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event factory_solver::on_gui_selection_state_changed (ID 62)
factory_solver/manage/info.lua:533: assertion failed!
stack traceback:
[C]: in function 'assert'
factory_solver/manage/info.lua:533: in function 'typed_name_to_craft'
factory_solver/ui/solution_editor.lua:49: in function 'handler'
flib/gui.lua:177: in function 'dispatch'
factory_solver/fs_util.lua:145: in function 'dispatch_to_subtree'
factory_solver/ui/solution_selector.lua:62: in function 'handler'
flib/gui.lua:177: in function <flib/gui.lua:160>

Fixed in version 0.1.6. Thanks again for the next report!