Error code on website and email error

I know this is a large post and huge request but I really need help!

I am using WP 3.3, CC Pro 0.7 & the newest Buddy Press version. Last week I did an upgrade from windows to linux. I think that may be where this issue came from?I think I may have found the issue but dont know how to fix it. To speed up my site Ive been running w3 total cache and my site is also cloudflare powered for acceleration. When i updated to linux my w3 total cache was deactivated for some reason and it kept giving me an error when trying to reactivate it that said it could not be reactivated because of a fatal error. It also would not let me delete it.
The warning on my page is
Warning: Unknown: open(/var/chroot/home/content/46/8650646/tmp/sess_93r83thoa7ot1dqp5fn1juh1r5, O_RDWR) failed: No such file or directory (2) in Unknown on line 0

Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct () in Unknown on line 0

The files referred to on the error code at the bottom of my website are not found anywhere on my ftp file manager/server and im wondering if they might be files somewhere on cloudflare or if it has something to do with w3 total cache? Any bright ideas? or does this not make sense? My site is https://www.ifitsfreegivemethree.com if you want to go look at the error codes. They show up at the bottom of every page.

Looks like something to do with being able to find the file on my server? or that the file is set up wrong? I need to be able to find the file or process that is pointing to the missing file so I can figure out the problem.

I manually deleted w3 total cache with all associated files via FTP and reinstalled w3 total cache to try and find if the problem was associated. When w3 cache is activated it tells me that my Linux server configuration may not be set up for .htaccess.

Also, my new users stopped receiving activation emails so they cant activate their member account and login. They have checked their junk mail multiple times with no success. Im not sure what happened or how to trouble shoot this because there are no options that i can find for activation emails, etc. I tried to sign in with a members creds to test what is happening and the error codes i got were ” your account has not been activated. Check your email for the activation link” (which is understandable considering they never got the activation email).

Any ideas would be great! Thanks.