Trouble with scanning and firewall

Hi,
I am having trouble scanning and setting up the firewall.

For the scanning i have tried numerous things suggest on forums and posts all to no avail. It seems to hang on the following steps:

Scanning file contents for infections and vulnerabilities
Scanning files for URLs in Google’s Safe Browsing List

When i enable debugging mode it seems to hang on:

Scanning contents: wp-content/themes/Divi/includes/builder/functions.php (Size:249946B Mem:74.2M)

I am currently running with:

Maximum execution time for each scan stage: 10
How much memory should Wordfence request when scanning: 20 (i previously took this up to 300)

As for the firewall i am on a shred hosting at Arvixe and have multiple sites running but i was a little confused how to set this up as the wizard did not complete.

It currently says:

We were unable to make changes to the .htaccess file. It’s possible WordPress cannot write to the .htaccess file because of file permissions, which may have been set by another security plugin, or you may have set them manually. Please verify the permissions allow the web server to write to the file, and retry the installation.

But im sure it previously said something about a multi site isntall and php.ini.

Thanks in advance