White screen on page/post update, plugin update settings and activate plugin

Hello boys and girls,

after transferring website from one host to another, I’ve started getting white screen on page/post update, plugins update settings and activate plugin buttons.

The strange thing to me is that all settings apply(page updates and then goes white screen, plugin gets activated etc).

I took a look at Bluehosts cPanel log errors, and this is what I found out:

In main error_log I’m getting this errors(every time the white screen appear):

https://pastebin.com/1C9WDZMp (you will notice that all of them appear in few seconds)

In PHP error_log I’m getting this errors(one error per white scren):

[06-Oct-2012 15:31:48] PHP Warning: Cannot modify header information - headers already sent by (output started at /home4/surveyt5/public_html/wp-content/themes/thesis_185/lib/classes/loop.php:1) in /home4/surveyt5/public_html/wp-includes/class-wp-ajax-response.php on line 129

(sometimes pluggable.php instead class-wp…)

What I’ve tried so far:

Disable/Enable all plugins and theme.

RewriteRule ^(.+)$ /index.php/$1 [L,QSA] .htaccess fix for the main log error.

Checked for empty spaces in loop.php.

I’m opened for any idea ??

Thank you.