I have a Merlin Legend, Version 7 Release 1. I began installing a new Esna-Tech TOL 2000 voice mail. I knew that the system had extensions with 2 digit and 4 digit (default 71xx) extension numbers. I tried to make it work because the TOL will support different mailbox lengths, but it doesn't support different extension lengths. So, I tried to change the 4 digit to 2 digits. I just got an error tone. Does the system need to be idle? I went to System Programming, Sysrenumber, Single, Extensions, Single.