HI Julian,
if the area doesn't show up in the monitor, please try to start the constructor in transaction SHMM on your own by selecting the icon 'Start Constructor' as shown in the screenshot.
Choose CL_RIS_SHM_AREA as area, select 'Default Instance' and 'Dialog' as execution mode. Then press 'Create'. Either this works or the system will tell you the issue with the instance creation (e.g. insufficient shared objects memory - see the other solution description).
Best regards, Sebastian