In R News we read:
Calling && or || with an argument of length greater than one now gives a warning (and it is intended that will eventually become an error).
This broke the following line of code in the r2d3 package (v0.2.5):
https://github.com/rstudio/r2d3/blame/388585b7f863f9ec0c9549a77025908e1fb37ecb/R/script.R#L33
Which produced warnings in modelStudio(); thus, errors in CRAN checks.
Should be solved when r2d3 v0.2.6 arrives at CRAN. rstudio/r2d3#98