jprovost

Resolved—deactivated all plugins, then reactivated one-by-one. WordPress Firewall 2 was to blame.

Update: I just successfully created another addon/parked domain subsite… meaning the problem with subdomain subsites has to be with the subdomain wildcard, right??

Wildcard subdomains worked in the past, ie *.domain1.com. = ip.address

I used to have test.domain1.com and one day it stopped working, I couldn’t access it or /wp-admin/

I’ve tried with and without plugins activated, no luck.

Further to all this, I’ve since reinstalled WordPress to try and address another problem and it has solved this one. The new .htaccess is working fine so far.

For the benefit of anyone who finds their way here, this is what my .htaccess at /www/ looks like:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# uploaded files
# RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2&path=$1 [L]

#domain1
RewriteCond %{HTTP_HOST} ^domain1.com\.com$ [NC]
RewriteRule ^files/(.+) wp-content/blogs.dir/1/files/$1 [L]

#domain2
RewriteCond %{HTTP_HOST} ^domain2\.org$ [NC]
RewriteRule ^files/(.+) wp-content/blogs.dir/5/files/$1 [L]

#domain3
RewriteCond %{HTTP_HOST} ^domain3\.ca$ [NC]
RewriteRule ^files/(.+) wp-content/blogs.dir/8/files/$1 [L]

#domain4
RewriteCond %{HTTP_HOST} ^domain4\.com$ [NC]
RewriteRule ^files/(.+) wp-content/blogs.dir/14/files/$1 [L]

#...the rest of the rename rules follow this.

Supercache also greatly reduced my server memory and CPU usage.

Update: It seems that ms-files.php was hanging, delivering incomplete file headers, and using up all of my shared hosting resources.

The following .htaccess rules resolved my problem. They seem to bypass ms-files.php completely, instead redirecting requests from domain.tld/files/ to domain.tld/wp-content/blogs.dir/#/files/

RewriteCond %{HTTP_HOST} ^domain\.tld$ [NC]
RewriteRule ^files/(.+) wp-content/blogs.dir/#/files/$1 [L]

Be sure to replace domain.tld AND the # with the blog id number.