Hello,
Please go to file:
components/com_booklibrary/booklibrary.php on line 626
and code
sendMailRentRequestCB($datas,_BOOKLIBRARY_LENDREQUEST_EMAIL_ACCEPTED);
replace to :
PHP_booklibrary:endMailRentRequestCB($datas,_BOOKLIBRARY_LENDREQUEST_EMAIL_ACCEPTED);
And for you all will good.
Thanks,
OrdaSoft team