I'm getting a crash when attempting to migrate my 0.17 save with Miniloader-1.9.0

The mod Miniloader caused a non-recoverable error.
Please report this error to the mod author.

Error while running event miniloader::on_configuration_changed
LuaEntity API call when LuaEntity was invalid.
stack traceback:
miniloader/lualib/util.lua:112: in function 'belt_side'
miniloader/configchange.lua:237: in function 'f'
miniloader/configchange.lua:19: in function 'forall_miniloaders'
miniloader/configchange.lua:236: in function 'task'
miniloader/configchange.lua:270: in function 'on_mod_version_changed'
miniloader/control.lua:73: in function <miniloader/control.lua:70>
stack traceback:
[C]: in function 'index'
__miniloader/lualib/util.lua:112: in function 'belt_side'
miniloader/configchange.lua:237: in function 'f'
miniloader/configchange.lua:19: in function 'forall_miniloaders'
miniloader/configchange.lua:236: in function 'task'
miniloader/configchange.lua:270: in function 'on_mod_version_changed'
miniloader/control.lua:73: in function <miniloader/control.lua:70>

I'm getting a similar issue. Source MiniLoader version was 1.8.5

Should be fixed in v1.9.1.

Looks like that did the trick. Thanks!

The crash is fixed, but instead I now have a bunch of belts/splitters spread around, as if existing assets had been duplicated and laid on the ground. Many got picked up by belts and put in wagons, paralyzing my factory o0
Roughly 50% are blue belts/splitters (the ones I have everywhere) but they usually have a yellow belt/splitter next to them I have no idea come from. Some spots also had a ton a material that used to be on the belt (steel, science packs...) laid on the ground (roughly 70/spots)
Any idea where it come from?

I just noticed that bug myself. If you still have the 0.17 map, try migrating it into v1.9.2. I'm a little surprised that Factorio allowed those items to be picked up by adjacent belts.

The migration uses "fast replace" logic. I suspect the problem is when the fast-replace hits an underground-belt, and the items in the underground "inventory" temporarily no longer have a place to be. Currently in v1.9.2 any excess items are simply deleted. It's not ideal, and I'll have to try to think of a better fix.

Indeed, appear to be fixed! Thanks!