进入后台更新文件显示“Server Error in '/' Application”求高手解决

Question

ExecuteScalar requires an open and available Connection. The connection's current state: Broken.
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.InvalidOperationException: ExecuteScalar requires an open and available Connection. The connection's current state: Broken.

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.

求高手这个问题怎么解决，两个小时前一切还是正常的，包括更新与上传。