The telescope crashed the save when leveling up

The mod Machine Levelup (1.0.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event machine-levelup::on_tick (ID 0)
The mod ○🌐Muluna, Moon of Nauvis (2.2.100) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event planet-muluna::script_raised_built (ID 92)
planet-muluna/scripts/telescopes.lua:66: Ghost telescope placed by entity that is neither a player nor robot.
stack traceback:
[C]: in function 'error'
planet-muluna/scripts/telescopes.lua:66: in function 'func_to_run'
planet-muluna/lib/events.lua:50: in function <planet-muluna/lib/events.lua:47>
stack traceback:
[C]: in function 'apply_upgrade'
machine-levelup/control.lua:107: in function 'filter'
machine-levelup/buckets.lua:43: in function 'filter_bucket'
machine-levelup/control.lua:112: in function <machine-levelup/control.lua:111>

Thanks for the report, I thought I resolved this issue already but apparently it fell through. Will look into it.

I reached out to the muluna dev since I would not have been able to resolve this from machine-levelup's side (only possible workaround would've been to ignore telescopes completely).

So this should be fixed with muluna 2.5.15. But that means you'd have to switch to the 2.1 experimental branch or wait until 2.1 hits stable.