预览.aspx页面时出现的问题

我在预览.aspx页面时，出现了错误，有如下的代码：
Server Error in '/' Application.
--------------------------------------------------------------------------------

Unable to retreive configuration section 'system.web/healthMonitoring'.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Configuration.ConfigurationException: Unable to retreive configuration section 'system.web/healthMonitoring'.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[ConfigurationException: Unable to retreive configuration section 'system.web/healthMonitoring'.]