This post will walk you through fixing the RHEV/oVirt error shown below. Note that this error was received when trying to load the RHEV-M/oVirt Engine web interface.
Note that these instructions worked for me in a known working environment, where the web interface was previously working but had failed after an unscheduled restart of the host.
First lets restart the ovirt-engine.
# service ovirt-engine restart
Stopping oVirt Engine: [FAILED]
Starting oVirt Engine: [ OK ]
Next we restart the ovirt-websocket-proxy
# service ovirt-websocket-proxy restart
Stopping oVirt Engine websockets proxy: [ OK ]
Starting oVirt Engine websockets proxy: [ OK ]
Finally, we restart Apache.
# service httpd restart
Stopping httpd: [ OK ]
Starting httpd: [ OK ]