It's impossible to create subscription from the billing, the page is always loading in circle and ends up on a page not found. The following error message can be found in the logs:
[01-Apr-2015 02:33:34 America/New_York] PHP Fatal error: Allowed memory size of 3384803328 bytes exhausted (tried to allocate 632 bytes) in /opt/plesk-billing/lib/billing-libs/Billing/Database/PdoQuery.php on line 31
The issue caused by large billing cache. CBM should cleanup cache data and should not use all memory. This issue is confirmed as internal issue with id #PPPM-2693; the fix is considered to be included in one of the next updates.
As possible temporary workaround for this issue you can clean the cache and restart
# /usr/share/plesk-billing/cache -c # service sw-engine restart
To avoid this issue in future we can recommend you to increase
memory_limit value in the
/usr/local/psa/admin/conf/php.ini (for example: double this value for future).
Also you can create a
cron task to clean cache once a month.