You have migrated to WebSphere MQ V7.1.0 and want to use CFLEVEL(5) for your CF (Coupling Facility) structure, but it fails when defining or altering a CF structure.
CSQY334E _CSQ1 CSQMACFS CFLEVEL(5) not allowed - restricted functionality
All queue manager in a QSG( queue sharing group) are not running V7.1.0 and started with OPMODE(NEWFUNC). This is the requirement to use CFLEVEL(5). This is documented in the WebSphere MQ Information Center.
Resolving the problem
Ensure that each of the queue managers in the QSG is running V7.1.0 and with OPMODE(NEWFUNC). Then you are able to define the CFSTRUCT as CFLEVEL(5).