After Plesk upgrade the following error is shown on the Home page:
ERROR: Class 'Base_Exception' not found (SyntaxException.php:11)
The following error is shown in the
2013/07/22 05:36:08 [error] 15446#0: *143 FastCGI sent in stderr: "PHP message: PHP Warning: psasem_rinit(): failed to open semaphore file: /usr/local/psa/var/psasem.sem: Permission denied in Unknown on line 0" while reading response header from upstream, client: 126.96.36.199, server: , request: "POST /signout HTTP/1.1", upstream: "fastcgi://127.0.0.1:19001", host: "188.8.131.52:8443", referrer: "https://%plesk_hostname%:8443/logout.php3"
Plesk was not upgraded correctly.
Reinstall base packages of Plesk 11.5 manually. Distributive of Plesk is located on the http://autoinstall.plesk.com website.
The example for Plesk 11.5 for CentOS5, 64-bit:
# /usr/local/psa/admin/sbin/autoinstaller --select-release-current --reinstall-patch --install-component base