Question: I'm developing a `winform` application in C# and everything was fine. But all of a sudden I get this weird error when I tried to run the application.

> 
> Namespace '' contains a definition conflicting with alias 'PersianDate'
> 
> 
> 

This is the line which throws the error.

```
private PersianDate _quotationDate;

```

All I done before getting the error was to add this `form_load` event.

```
private void frmAddDragSource_Load(object sender, EventArgs e)
 {
   this.Text = "Source";
 }

```

Does anyone knows why this happens and how can I fix it?

**UPDATE** 
my usings:

```
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlServerCe;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using FishTablighPro.Utility;
using PersianDate = FreeControls.PersianDate;

```

Answer: 
Since you defined `PersianDate` as an alias for the `FreeControls.PersianDate` namespace. The compiler can't tell whether by `PersianDate` you refer to the namespace alias you created, or to the `PersianDate` type defined in it.

Try to point directly to the `PersianDate` *Type*:

```
private PersianDate.PersianDate _quotationDate;

```
My guess: The following definition..

```
using PersianDate = FreeControls.PersianDate;

```

... is conflicting with the attempted variable definition:

```
private PersianDate _quotationDate;

```

Here, `PersianDate` seems to refer to a namespace, and not a type that you would use for a variable. 

If you really need the shortcut to the namespace, change it to something else so it does not conflict with the type. Otherwise, specify the whole namespace to the `PersianDate` type for the variable - that should work too, since it would then become clearly distinct from your other namespace. 

Edit: Are these actually referring to the same namespace? If so, you could use either:

```
// If you for some reason absolutely want to use an alias
// (perhaps to avoid some other naming conflict..?)
using pd = FreeControls.PersianDate;
...
private pd.PersianDate _quotationDate; 

```

...or, if there is no conflict anyway (ie no other imported type available with the same class name `PersianDate`), simply:

```
using FreeControls.PersianDate;
private PersianDate _quotationDate; 

```