Contact publisher ERROR

[anamaria]

hi. I realy need your help guys and I hope someone can help me.
I try to contact the seller (Contact publisher)and I have this error:

Warning: Illegal string offset 'name' in /home2/anamaria/public_html/ilannuncio.com/oc-includes/osclass/emails.php on line 640

Warning: Illegal string offset 'tmp_name' in /home2/anamaria/public_html/ilannuncio.com/oc-includes/osclass/emails.php on line 641

Warning: Cannot modify header information - headers already sent by (output started at /home2/anamaria/public_html/ilannuncio.com/oc-includes/osclass/utils.php:1710) in /home2/anamaria/public_html/ilannuncio.com/oc-includes/osclass/utils.php on line 1715

I tried several possibilities found here on the forum but nothing. I can not solve this problem.

Ossclass version they use is osclass.3.4.1

Thank you!