We call those warnings, and it's very common to downgrade errors to warnings by wrapping an exception and printing the trace as you would an exception.
Warnings are just errors that no one wants to deal with.
mostly though when you are on a known problem warnings should be a useful filter to find where in the logs the problem might have started, then you use that timestamp to find info logs in the same area
Anything that has a measurable impact on production should be logged above that, except if your system ignores log levels in the first place, but that's another can of worms.