SetOptions error message upon launching Mathematica v.12

When launching Mathematica v.12, before opining any notebook, I get the following message: enter image description here

It does not afffect the execution of my notebooks, but it is annoying and I would like to understand how to get rid of it. I have read similar and previous questions/answers. I took a loook at the init.m file, but it is exceedingly involved. Is there a way to reset the Argument Label Style option and how? Your help will be greatly appreciated.