Hello

Unfortunately error during underground belt upgrade is back with version 2.0.3. It occurs during selecting for upgrade underground belts that are already selected for it before from overworld. That causes cascade of errors (at least it seems like it works this way). I have seen similar thread about error with upgrading on version 2.0.0, I am not sure if this is anything related or not.

Logs: drive.google.com/file/d/1ky2fYV9k38A_IjBzwy-ZTbF0UDtI1mXs/view?usp=sharing
Save: drive.google.com/file/d/1egIOCPdIVHB2fS2-ojVsjkpcxYEmhN2o/view?usp=sharing

If you need any other stuff such as all the other modlist version, let me know. But so far I could replicate that interaction just with beltlayer.

Can you provide detailed reproduction steps? I don't know what you mean by "selecting for upgrade underground belts that are already selected for it before from overworld."

There is a infinite loop when using upgrade plan or deconstructor plan on underground connectors. Adding simple checks fixes this (in Editor.lua add "counterpart.to_be_upgraded()==false" to line 412 and "counterpart.to_be_deconstructed()==false" to line 424).
Another problem is that when upgrading normal underground pieces (ie: belts, splitters and underground belts), construction bots don't get the old piece back, so instead they extract constant combinator. From what I have gathered from source code; problem is that bots can't access the underground piece and just take the above ground proxy piece.

Thank you for the report on the infinite loop. It looks like there was a change in base Factorio game behavior, where before events were not raised when ordering an upgrade on an entity that was already so marked. I am not able to reproduce the infinite loop when deconstructing.

The upgrade loop and problems with bots taking constant combinators should be fixed now in v2.0.4.

@therax - Thank you, tested working on my setup.

@Qrusis - Ah that explains where all those constant combinators in my inventory came from lol.