TransmitMailが動きません。500エラーが出てしまいます

[Masaki-G]

aws ec2にホストしています

[ec2-user@ip-172-31-38-97 config]$ php -v
PHP 7.4.33 (cli) (built: Nov 19 2022 00:22:13) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
[ec2-user@ip-172-31-38-97 config]$

/regist/bank/にアクセスすると500エラーが出ます

ログには下記のように出ています

[ec2-user@ip-172-31-38-97 log]$ tail -f error.log
[13-Jun-2019 11:37:58 Asia/Tokyo] PHP Warning:  mb_convert_kana() expects parameter 1 to be string, array given in /xxxx/TransmitMail.php on line 572
[13-Jun-2019 11:44:43 Asia/Tokyo] PHP Warning:  mb_convert_kana() expects parameter 1 to be string, array given in /xxxx/TransmitMail.php on line 572
[13-Jun-2019 11:44:47 Asia/Tokyo] PHP Warning:  mb_convert_kana() expects parameter 1 to be string, array given in /xxxx/TransmitMail.php on line 572
[13-Jun-2019 11:44:53 Asia/Tokyo] PHP Warning:  mb_convert_kana() expects parameter 1 to be string, array given in /xxxx/TransmitMail.php on line 572
[13-Jun-2019 11:45:04 Asia/Tokyo] PHP Warning:  mb_convert_kana() expects parameter 1 to be string, array given in /xxxx/TransmitMail.php on line 572
[13-Jun-2019 11:45:59 Asia/Tokyo] PHP Warning:  mb_convert_kana() expects parameter 1 to be string, array given in /xxxx/TransmitMail.php on line 572
[13-Jun-2019 12:46:54 Asia/Tokyo] PHP Warning:  filesize(): stat failed for https://example.net/thanks_bank/ in xxxx/tinyTemplate.php on line 79
[13-Jun-2019 12:46:54 Asia/Tokyo] PHP Warning:  fread(): Length parameter must be greater than 0 in xxxx/tinyTemplate.php on line 79
[13-Jun-2019 12:57:51 Asia/Tokyo] PHP Warning:  filesize(): stat failed for https://example.net/thanks_bank/ in xxxx/tinyTemplate.php on line 79
[13-Jun-2019 12:57:51 Asia/Tokyo] PHP Warning:  fread(): Length parameter must be greater than 0 in xxxx/tinyTemplate.php on line 79