The value specified by the matelsn parameter must indicate an existing linkset.
Recovery
Display the existing linksets. Enter the rtrv-ls command.
Create a new linkset to assign as the mate linkset, or re-enter the chg-ls command that generated this error message, specifying an existing linkset as the value for the matelsn parameter. Refer to the Database Administration - SS7 User's Guide (SS7 linkset) Database Administration - IP7 User's Guide (IP linkset) for assistance.