I am having a file permission error that seems can only be solved by the host.
if it is a issue with [ Mod_Security ] ...
Mod_Security is a Web Application Firewall (WAF) that filters and blocks known malicious HTTP requests. Blocked HTTP requests include many, but not all forms of Brute Force, Cross-Site Scripting (XSS), Remote File Inclusion (RFI) , Remote Execution, and SQL injection (SQLi) attacks.
while x10hosting discourage it - Premium account users have the ability to completely disable [ mod_security ] on their account via cPanel
For free-hosting x10hosting has a customized web server setup that does not allow for the same cPanel functionality to disable [ mod_security ] - x10hosting also decided it would not be a good idea to allow free-hosting users to disable it - as it is used to not only protect against inbound malicious attacks but to prevent outbound abuse also - Unfortunately free-hosting still gets abusive signups - and allowing them to disable something that helps to prevent their malicious actions would not be in x10hosting's best interest
if it is a issue with permission(s) are 0777 ...
make sure all file permissions are 0644 (rw-r--r--) and all folder permissions are 0755 (rwxr-xr-x)
IF 'permissions' set on any folder or file - in your account - are [ 777 ] - that makes a large security risk - so a x10hosting's free-hosting server will throw an immediate "Access Denied" (403 error code) error to protect itself
BTW - what is the error code (number) you receive ?