Category Archives: .Net

FileNet Error: HTTPS is Required

I am trying to push documents to FileNet using .Net 4.5 console application. This program is working fine on one machine but it does not work on another machine. I get the following error when I execute it: This error comes from FileNet.Api.dll. I tried to change the URL with https but it gave another […]

VB .Net – Calling a Function Calls Property Setter Method

I encountered a nasty bug (technically: design) when I was using an HTML Web control in a WinForms application. I am storing html and plain text version of text into a SQL table. This control has InnerHtml and InnerText properties. Both of these properties have getter and setter. I was calling a 3rd party dll […]

.Net 3.5 System.Web.UI.DataVisualization namespace does not exists

I was trying to compile an inherited VB .Net code that uses .Net 3.5 framework. When I compiled, it gave the following error The type or namespace name ‘DataVisualization’ does not exist in the namespace ‘System.Web.UI’ (are you missing an assembly reference?) Whatever answers I tried to find online could not give me details for […]

Weird errors for VB .Net classes defined in App_Code folder

Recently I was making a .Net 3.5 webforms application compile on my computer. The application was written in VB .Net. There were couple of classes which were causing weird issues. Visual Studio compiler generated “variable not declared”, “Exception not declared”, “End Sub does not have matching sub”, “line continuation character does not work in VB […]

How to run a single instance of WinForm application?

Following tutorial provides an example to run a single instance of WinForms application using Mutex. There are multiple ways to achieve the same result but this is kind of neat solution in my opinion. Add following SingleInstance class in your project. Here is how to use it in Program.cs > Main function


Mailto Invalid URI: The Hostname Could Not be Parsed.

If the Uri is “mailto”, the Uri format must be in the following format. I encountered following error It was difficult to find the root cause. Finally I found that I used “&subject” (ampersand) for the first parameter instead of “?subject” (question mark). Once I used “?subject”, everything worked as expected.