When you reallocate a WLM couple data set, it must be at least as large as the current one or you will not be able to make it available to the sysplex. It is recommended that you increase the size of your couple data set to allow you to exploit new functions, even if you do not plan to exploit new functions immediately.
Use the WLM ISPF Application Utilities option (see Utilities) with the “Allocate couple data set using CDS values” option to determine your couple data set size. If you already have a record of the values, you can skip this step; just ensure you allocate the WLM couple data set with the same or larger values as the current one.