Stored Procedure General error: 1267 Illegal mix of collations

I have stored procedure and i am trying to call from laravel application and i am getting this error.

Stored Procedure

CREATE DEFINER=`root`@`localhost` PROCEDURE `SubjectAllocation`(
	IN coursesin VARCHAR(25),
	IN regulationsin VARCHAR(25),
	IN batchin VARCHAR(25),
	IN semesterin VARCHAR(25)
)
BEGIN
DROP TEMPORARY TABLE IF EXISTS `subjectassign`; 

CREATE TEMPORARY TABLE `subjectassign` (
		`subject_id` INT, `student_id` INT,
		`subjecttype_id` INT
	); 
INSERT INTO `subjectassign`
SELECT
	`subjects`.`id`,
	`students`.`id`,
	`subjects`.`subjecttype_id`
FROM
	`subjects`,
	`students`
WHERE
	`subjects`.`programme_id` = `students`.`programme_id`
	AND `subjects`.`regulation_id` = `students`.`regulation_id`
	AND `subjects`.`course_id` = `students`.`course_id`
	AND `subjects`.`semester` = semesterin
	AND `students`.`regulation_id` = regulationsin AND `students`.`course_id` = coursesin
	AND `students`.`batch_id` = batchin; 
	DELETE `subjectassign`,`exam_applications`
FROM
	`subjectassign`
	INNER JOIN `exam_applications` ON `subjectassign`.`student_id` = `exam_applications`.`student_id`
	AND `subjectassign`.`subject_id` = `exam_applications`.`subject_id`; INSERT INTO `exam_applications`(
		`student_id`, `subject_id`, `exammonth_id`,
		`examtype_id`, `exampapertype_id`,
		`verification`, `display`)
SELECT
	DISTINCT `student_id`,
	`subject_id`,
	`subjecttype_id`,
	'N',
	'Y'
FROM
	`subjectassign`; 
	
	END

Schema Collation:utf8mb4_unicode_ci