Error message

Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Notice: Trying to access array offset on value of type int in element_children() (line 6592 of /home1/montes/public_html/books/includes/common.inc).
Deprecated function: implode(): Passing glue string after array is deprecated. Swap the parameters in drupal_get_feeds() (line 394 of /home1/montes/public_html/books/includes/common.inc).
Deprecated function: The each() function is deprecated. This message will be suppressed on further calls in menu_set_active_trail() (line 2405 of /home1/montes/public_html/books/includes/menu.inc).