1.
PHP & MySQL: mysqli_num_rows() expects parameter 1 to be…
stackoverflow.com/questions/2546314/php-mysql-mysqli-num-rows-expects-parameter-1-to-be-mysqli-result-boolean
2.
[SOLUTION] Warning: Mysqli_num_rows() Expects Parameter 1 to…
errorsea.com/solution-warning-mysqli_num_rows-expects-parameter-1-to-be-mysqli_result/
3.
[Solved] Warning: mysqli_num_rows() expects parameter 1 to be…
www.codeproject.com/Questions/391831/Warning-mysqli-num-rows-expects-parameter-1-to-be
4.
Warning mysqli_num_rows() expects parameter 1 to be…
github.com/bcit-ci/CodeIgniter/issues/1614
5.
Warning: mysqli_num_rows() expects parameter 1 to be… – PHPHelp
www.phphelp.com/t/warning-mysqli-num-rows-expects-parameter-1-to-be-mysqli-result/26288
6. 
PHP: mysqli_result::$num_rows – Manual
www.php.net/manual/en/mysqli-result.num-rows.php
7.
Mysqli_Num_Rows() Expects Parameter 1 To Be Mysqli_Result…
larryullman.com/forums/index.php?/topic/3088-mysqli_num_rows-expects-parameter-1-to-be-mysqli_result-boolean-given-array/
8.
Solved: mysqli_num_rows() expects parameter 1 to be…
www.experts-exchange.com/questions/26419905/mysqli-num-rows-expects-parameter-1-to-be-mysqli-result-boolean-given-in-HELP.html
9.
MySQL :: MySQL PHP API :: 3.10.18 mysqli_result::$num_rows…
dev.mysql.com/doc/apis-php/en/apis-php-mysqli-result.num-rows.html
10.
mysqli_num_rows – Возвращает количество строк в результате
htmlweb.ru/php/function/mysqli_num_rows.php
11.
How to report errors in mysqli – Treating PHP Delusions
phpdelusions.net/mysqli/error_reporting
Conclusion
Guide above should be useful for Mysqli_num_rows() Expects Parameter 1 To Be Mysqli_result.