A severe error occurred on the current command. The results, if any, should be discarded. -- 2

My app is having ramdom server error check below and try to fix from root. Server Error in '/' Application. A severe error occurred on the current command. The results, if any, should be discarded. A severe error occurred on the current command. The results, if any, should be discarded. 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: [login to view URL]: A severe error occurred on the current command. The results, if any, should be discarded. A severe error occurred on the current command. The results, if any, should be discarded. Source Error: Line 88: DataSet ds = new DataSet(); Line 89: SqlDataAdapter da = new SqlDataAdapter(sql, connectionstring); Line 90: [login to view URL](ds); Line 91: return ds; Line 92: } Source File: d:\InetPub\vhosts\[login to view URL]\[login to view URL]\App_Code\[login to view URL] Line: 90