After some ~50 years in game, the dashboard stops processing new saves, and outputs an error. The database always successfully rolls back, but the dash doesn't get updated again.

This is with a relatively heavily modded game. If the mod list is requested, it can be provided.

I can't think of a particular planet modifier that might be causing it.

Short log error:
InvalidRequestError: Instance '<PlanetModifier at 0x26c2396588>' has been deleted


Full error:
2019-09-07 06:30:53,807 - stellarisdashboard.timeline - INFO - unitednationsofea
rth_-15512622 2250.03.03 done (4.878 s)
2019-09-07 06:30:53,808 - stellarisdashboard.timeline - INFO - unitednationsofea
rth_-15512622 2250.03.03 - Processing sectors_colonies
2019-09-07 06:30:54,057 - stellarisdashboard.timeline - ERROR - unitednationsofe
arth_-15512622 2250.03.03 Rolling back changes to database...
Traceback (most recent call last):
File "C:\Users\User\Desktop\stellaris-dash_2\stellarisdashboard\timeline.py"
, line 54, in process_gamestate
self._process_gamestate(game_id)
File "C:\Users\User\Desktop\stellaris-dash_2\stellarisdashboard\timeline.py"
, line 87, in _process_gamestate
{key: all_dependencies[key] for key in data_processor.DEPENDENCIES}
File "C:\Users\User\Desktop\stellaris-dash_2\stellarisdashboard\timeline.py"
, line 1224, in extract_data_from_gamestate
self._history_add_planetary_events_within_sector(country_model, system_id, g
overnor_model)
File "C:\Users\User\Desktop\stellaris-dash_2\stellarisdashboard\timeline.py"
, line 1260, in _history_add_planetary_events_within_sector
self._history_add_or_update_colonization_events(country_model, system_model,
planet_model, planet_dict, governor)
File "C:\Users\User\Desktop\stellaris-dash_2\stellarisdashboard\timeline.py"
, line 1300, in _history_add_or_update_colonization_events
self._session.add(planet_model)
File "C:\Users\User\Desktop\stellaris-dashboard-master\env\lib\site-packages
\sqlalchemy\orm\session.py", line 1835, in add
self._save_or_update_state(state)
File "C:\Users\User\Desktop\stellaris-dashboard-master\env\lib\site-packages
\sqlalchemy\orm\session.py", line 1855, in _save_or_update_state
self._save_or_update_impl(st_)
File "C:\Users\User\Desktop\stellaris-dashboard-master\env\lib\site-packages
\sqlalchemy\orm\session.py", line 2165, in _save_or_update_impl
self._update_impl(state)
File "C:\Users\User\Desktop\stellaris-dashboard-master\env\lib\site-packages
\sqlalchemy\orm\session.py", line 2139, in _update_impl
state_str(state)
sqlalchemy.exc.InvalidRequestError: Instance '<PlanetModifier at 0x26c2396588>'
has been deleted. Use the make_transient() function to send this object back to
the transient state.
2019-09-07 06:30:54,073 - stellarisdashboard.visualization_data - INFO - Loaded
0 new gamestates from the database in 0.003 seconds. (81 gamestates in total)
2019-09-07 06:30:54,098 - stellarisdashboard.cli - INFO - Waiting for new saves
in C:\Users\User\Documents\Paradox Interactive\Stellaris\save games