New installation error

I am getting the following html error message and the following entry in the error_log for a new installation of rt3. I am a newbie so am unsure of exactly what to look for. The rt-test-dependencies reports all perl mods found. Thanks in advance for your help.
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Apache/1.3.27 Server at Port 80

Contents in error_log:

[error] Can’t call method “handle_request” on an undefined value at /opt/rt3/bin/webmux.pl line 119.