When I want to add images on the form it always come up with one error- Method "Llabel1_Click" not found

Remove the stale Llabel1_Click assignment from the label’s Click event, or recreate that method if the label is supposed to respond to clicks.

Preferred fix: reset the Click event

The form still references Llabel1_Click, but that method was probably deleted or renamed. Microsoft recommends removing event handlers through the Properties window rather than deleting only their code, because the designer retains the event subscription ^1^.

1. Open the form in Design view.
2. Select the label associated with the error.
3. In Properties, select the lightning-bolt Events button.
4. Find Click.
5. If its value is Llabel1_Click, right-click the event and select Reset.
6. Save the form.
7. Select Build > Rebuild Solution.

You can then add images to the form normally. The Click event is unrelated to the image itself; the error appears while the designer is loading the form.

If the designer will not open

1. In Solution Explorer, expand the form and open FormName.Designer.cs.
2. Search for Llabel1_Click.
3. Remove only the event-subscription line resembling:

this.label1.Click += new System.EventHandler(this.Llabel1_Click);

Do not delete the label declaration or its initialization. Designer files are generated code, so make a backup or commit your changes first. A deleted or renamed handler that remains referenced in the designer is a documented cause of this type of design-time error ^2^.

Save, close and reopen the designer, and then rebuild the solution.

If the label should handle clicks

Instead of removing the subscription, restore the method in the form’s normal code file, such as Form1.cs:

private void Llabel1_Click(object sender, EventArgs e)
{
    // Code to run when the label is clicked.
}

The name, capitalization, and spelling must match the subscription exactly. In particular, check whether Llabel1_Click contains an accidental extra L and was intended to be label1_Click. A standard C# Click handler accepts object sender and EventArgs e ^3^.

After the designer opens, the safer way to generate a replacement is:

1. Select the label.
2. Open Properties > Events.
3. Double-click Click.

Visual Studio will create and connect a compatible handler automatically ^1^.

If the error remains

Use Build > Clean Solution, followed by Build > Rebuild Solution. If necessary, close Visual Studio, delete the project’s bin and obj folders, reopen the solution, and rebuild; these are the documented initial recovery steps for Windows Forms Designer errors ^2^.

References

1. How to handle a control event
2. Windows Forms Designer error page
3. How to subscribe to and unsubscribe from events (C# Programming Guide)