Hey,
after the update, the old rocket ports got removed. I tried to build them again with my bots. After the first one gets built, the game crashed with this error message.

Screen shoot: https://imgur.com/a/qqvL9hS

Some of my other mods got updated too, I can provide you with my save file.

Do you need further information?

Given that 'flawless' isnt a vanilla quality, theres a 95% chance this is an issue stemming from the interaction between this mod and whatever extra quality mod you're using. I need that mods' name (and versions, if it changed) to debug this.

Mining all rocket silos, uninstalling QRockets, loading and saving, and then placing the silos again manually likely will not crash.

You are right. Is Unlimited Quality-Mod ( https://mods.factorio.com/mod/unlimited-quality )

I use the default settings, with three new qualities, but there is an option for more.

Alright, the issue likely stems from that mod running in the stack after mine. I have taken steps to migate this possible issue, but apparantly this mod too decided to do the same.

With a hidden dependency, this should work now.

It is working. Great work! Thank you.