The following error message appears in Parallels Plesk Panel interface:
ERROR: Allowed memory size of 16777216 bytes exhausted (tried to allocate 86 bytes)
Operation requires more memory than allowed for Plesk's PHP backend. This may happen if object on which operation was executed has a complex structure.
memory_limit in Plesk's PHP configuration file:
/usr/local/psa/admin/conf/php.ini" on Linux
\admin\php.ini" on Windows
After changes are applied, restart Plesk control panel.