I don't have all the info you requested, but here is a screenshot from this morning.
The x error from RStudio is:
unexpected token ''
This is a file that was on my Desktop, so no network drives were involved.
When I view the characters in terminal using a more command, here is how they appear:
^@^@^@^@^@^@^@^@
Running the code works with no errors caused by the pink dots. So, the problem is one of annoyance and confusion about the code having errors.