Comments submitting error

When a comment is submitted, this error is displayed:
WInternal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webadmin@…com 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.”,
but then the comment is stored and displayed.
Has anybody idea of what kind of error is that?.Thanks