The Month-Day pair already exists (slogans)
This error occurs while importing Slogans from a text file, if Q++ notices that a Month-Day pair has been repeated. Common causes are
•Importing a text file with over 366 lines.
•Importing a text file into a non-empty Slogans Set, where the total number of entries is more than 366.
•Not understanding how the Month-Day Slogans Set type functions.
For more details, see Importing Slogans, and Slogans Sets.