I'm not sure what info to provide to help narrow down what's happening, but when I enable this mod many (but not all) mod-added ui elements (buttons and such) in the top left corner disappear. Disabling the mod brings them back.

Thanks for ur report.
I'm sorry but I don't have understand ur problem, I have only understand that the main wiki button disappear, from what I know the button still here always and can be added in an existing game. Can u help me giving me the steps to reproduce this bug?

I was able readily repeat the bug.

Existing K2 game showing rocket button, built-in K2 wiki, 'Factory Planner' button and (below) FNEI dialog:
https://i.imgur.com/H7z0mVZ.png

Enable Booktorio:
https://i.imgur.com/UWbWprk.png

Ahh my response never got submitted earlier. Yes mine is just like RepairmanSki shows. The krastorio wiki icon dissapears (as it should!) but also most of my other mods ui buttons dissapear as well when Booktorio is enabled.

I should have been slightly more clear in my submission. This is with the 'Booktorio Example' loaded, not just the Booktorio mod library.

Ok I have fix this error, was an error in K2 code not in Booktorio. The fix will be available in the next version of K2.