Problem(s) Encountered:

When trying to close the mirror, I received an error: “ERROR mirror mirror both open and closed.” Clicking the refresh button the control panel reset the mirror status, and clicking mirror 
then reported that mirror was opened. However, trying to close the mirror again resulted in the same error. I called the 2.4 observer to check if the mirror covers are actually closed. They reported all good, and also at some point in the process the error disappeared and the control panel reported that the mirror was closed.

Solution:

 This used to happen with more frequency in the past.  It is an odd state where the mirror covers are indeed closed, but the limit is not actuated.  Typically, this error can be ignored.