Troubleshooting on Legacy Survey App running on ASP.NET 2.0

We built this legacy application back in 2007 and have a major upgrade on 2009 and been running since then but then there is no much activity since 2014. Then reassure-ct again in late 2015.

Couple findings

  • Error on the session

This is a bit shock cause .cs file is never being change since 2009 !!!

Solution: Change the code accordingly to handle the missing handling of Session.

Find another one which is relating on Debug mode. Set: <compilation debug=”false”> in Web.Config. There is a possibility that there is a bug previously and didn’t set back into False.

  • Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

Turn out that the database server is registered under web.config still using the new production server. Need to change to a new server.

  • The application message came up: “You have a duplicate in MostLeast Preferred section. The option only can be used once of those questions. Please re-select it again.” Check the answer in the application and no duplicate answer.

Turn out that the actual matrix answer records in the database table has a duplicate for that particular question. Looks like entering twice. Not sure causing this at this stage. However by removing the duplicated entries, it solve the problem.


Exploring Dell iDrac


  • Certificates error when launching Virtual Console in Internet Explorer and having a white window/pop-up instead
    • The solution is to  upgrade the latest firmware for iDrac when having down time on the server or alternatively just use Firefox browser instead and this will launch Java Web Console instead. This solution is working well.

Exploring Hololens

Inspired Hololens projects

Microsoft HoloLens: Partner Spotlight with Trimble –

Microsoft HoloLens: Partner Spotlight with Volvo Cars –

Microsoft HoloLens: Partner Spotlight with Case Western Reserve University –

Microsoft HoloLens: Partner Spotlight with Autodesk Fusion 360 –

The evolution of Microsoft’s HoloLens –


Hololens development videos, documents, tools and many more – 

MVA Building Windows 10 Games with unity 5 –

Exploring Internet of Things (IoT) and Machine Learning

Predictive Maintenance Solution

Creating a solution will result in the following Azure services being provisioned:

  • Azure AD (1 Basic)
  • Azure IoT Hub (1 S2 Standard)
  • Azure Event Hub (1 Basic)
  • Azure Storage (2 GRS Standard)
  • Azure Stream Analytics (1 Streaming unit)
  • Azure App Services (2 Standard)
  • Azure Machine Learning Workspace (1)
Remote Monitoring Solution

Creating a solution will result in the following Azure services being provisioned:

  • Azure IoT Hub (1 high-frequency unit)
  • Azure Stream Analytics (3 streaming units)
  • Azure DocumentDB (1 S2 instance)
  • Azure Storage (1 GRS standard, 1 LRS standard, 1 RA-GRS standard)
  • Azure App Services (2 S1 instances, 2 P1 instances)
  • Azure Event Hub (1 basic throughput unit)


Internet of Things in General

Machine Learning

Machine Learning Tutorial: Create first experiment in Azure Machine Learning –


The Microsoft Cloud Platform for Developers (Glukose/heart rate/stress app monitoring app) –
Harness Predictive Customer Churn Models with Cortana Analytics Suite –