I have just done a fresh install of 2.6.5 (actually I've done it twice - just to be sure!) but I am encountering issues I can't seem to figure out. Occasionally in the admin menu, I get a 500 server error or blank page. The 500 error looks like this:
The following error occurred:
[code=SERVER_RESPONSE_CLOSE] The server closed the connection while reading the response. Contact your system administrator.
Please contact the administrator.