I got this message when I had Ore-ganizer and Omega drill mods activated after the last update.
Failed to load mods: ore-ganizer/prototypes/rmd-omega-drill.lua:41: attempt to index field 'radius_visualisation_specification' (a nil value)
stack traceback:
ore-ganizer/prototypes/rmd-omega-drill.lua:41: in main chunk
[C]: in function 'require'
ore-ganizer/data.lua:55: in main chunk

Thank you for reporting the issue, I will have it fixed asap.

Version 0.8.4 has been uploaded, it should resolve this issue.