hi i've been looking for hours how to fix this but with no luck, I'm very close to wiping everything and starting again!!!
I tried install W3 Total cache right after activating plugin I got:
500 Internal Server error. I've tried removing it via instructions I found but still get the error, the only way not to get the error is to delete the .htaccess file, but then my subdirectory sites don't work.
If I click on my sites from the drop down menu and select a site01 it goes to http://www.mysite.com/site01 it should go to http://www.site01.com.
I can go to http://www.site01.com directly but all my images are missing.
I'm sure it boils down to my .htaccess but all the suggested settings for my .htaccess bring up the 500 server error.
everything was running fine till I tried to put W3 Total cache on, I also noticed that when I followed the removal process of W3 Total cache that it had not installed all the files, so I removed what was there.
The annoying thing is that I did have a backup off .htaccess but for some reason when I opened the remote file it over wrote my local version even though I was never promoted to do so.