I received that same minify re-write error. I think just clearing your cache, and verifying your three htaccess files, you should be good to go.
If you are using a CDN such as Amazon, you should upload all your files once again, to get the new caching config working. Also try the new "Prime" button in the Page Cache setup. Click "Prime Cache".
More testing of all 4 of my websites after installing this new version, the initial first response of each site has dropped from about 8-10 seconds, to about .3 - .5 seconds. Amazing.