The newest version wont load for me.

19.855 Loading mod rubia 0.69.70 (data.lua)
19.910 Error ModManager.cpp:1758: Failed to load mod "rubia": rubia/lib/data-stage.lua:245: attempt to index local 'icondata_actual_source' (a nil value)
stack traceback:
rubia/lib/data-stage.lua:245: in function 'get_icon_data'
rubia/lib/data-stage.lua:305: in function 'make_rubia_superscripted_icon'
rubia/compat/crushing-industry.lua:16: in main chunk
[C]: in function 'require'
rubia/data.lua:52: in main chunk

I fixed it in 0.69.71.
I did not realize the Crushing Industry mod had a setting to turn off the concrete mix recipe chains.

I do have concrete mix enabled though.

In 0.69.71 the error is changed to:

20.507 Loading mod rubia 0.69.71 (data.lua)
20.563 Error ModManager.cpp:1758: Failed to load mod "rubia": rubia/lib/data-stage.lua:298: No icon data!
stack traceback:
[C]: in function 'assert'
rubia/lib/data-stage.lua:298: in function 'make_rubia_superscripted_icon'
rubia/compat/crushing-industry.lua:21: in main chunk
[C]: in function 'require'
rubia/data.lua:52: in main chunk

This mod works when I have Crushing Industry and Rubia installed, and concrete mix enabled. From that error, either 1) You have a third mod that deletes the concrete mix fluid (and maybe replaces it with a different one?), or 2) you have a third mod that changes the mod load order to make Rubia load before Crushing Industry.

Here is a bit of a faster way to find out what mod is the cause: If you could boot up the game without Rubia, press CTRL + SHIFT + E, that brings up the prototype explorer window. Search for "concrete-mix" under "fluid", and open its entry (it has a right arrow button next to it). A new window opens. search for "prototype history" (it should be in the first section), and open up that little list. It will give you a list of mods.
1) If the only mod you see there is "crushing-industry", then it means that it is a load order issue.
2) If you see another mod present, THAT is the third mod causing an issue.

If you could let me know what the result is, I could give a relevant fix quickly.

Alternatively, if you can provide the game log (factorio-current.log), that would also help me diagnose. Right now, I think it is a load order bug. I think I have a fix, but I can't put it out unless I can reproduce your bug.

Update: I figured it out. It is a mod load issue with several other mods. Working on it.

You're fast! Thanks.

Fixed in 0.69.72

Thanks! Seems to be working perfectly now.