Solved  - but solution might be helpful to other.

Somehow the upgrade and re-installation of the pluggin set (2.9.1 to 2.94) the permission on the mod files to 655. They need to be 644 to work. Manually lowering the permission fixed the problem. The permissions were had not been changed or set earlier by the server admin.

Hello,

On a 2.9.4. LAMP Moodle with the latest 2.9 Pluggin module.

When I attempting to open a  questionnaire I am now getting an Error 500. Upping the debugging didn't show any additional information.

http://mydomain.ca/mod/questionnaire/view.php?id=8950

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@training.apcapps.alphaplus.ca 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.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.