W3 Total Cache Plugin Crashed My Site- Help!

I just installed the W3 Total Cache plugin and I kept getting errors saying that it lacked permissions for certain folders. After I changed the permissions and tried to reactivate it, my site went down and I now get this error: “The server encountered an unexpected condition which prevented it from fulfilling the request.
The script had an error or it did not produce any output. If there was an error, you should be able to see it in the error log.” I looked in the error log, but I don’t see anything. Which error log should I be looking at? My site is hosted through iPage.com.