To reproduce:
-add RadSplitContainer (horizontal) and add one left and one right split panel
-add two RadButtons to collapse and show one of the panels
private void radButton1_Click(object sender, EventArgs e)
{
    this.splitPanel1.Collapsed = true;
}

private void radButton2_Click(object sender, EventArgs e)
{          
    this.splitPanel1.Visible = true;
}
-click the first button to collapse the left panel; as a result the second panel fills the entire container size
-click the second button to show again the left panel; as a result the panels overlap each other

In design time when trying to copy-paste a RadSplitContainer, which contains a couple panels, it throws exception.

Steps to reproduce:
Add a RadSplitContainer to a form or user control.
Add a couple of panels to the container using the designer.
Press Ctrl+A to select all the controls on the form or user control.
Press Ctrl+C to copy them to the clipboard.
Create a new form or user control (this step isn't strictly necessary, but helps explain the issue).
Paste the controls on the clipboard into the new form or user control using Ctrl+V

To reproduce:
- Set the splitter size to 40.
- Drag the splitter without releasing the mouse.
- The mouse pointer is in the beginning of the splitter, but it should be in its center.

When you try to copy and paste RadSplitContainer from one form to another, it loses its child panels and if it contains any other child controls, they become children of the form.

Sometimes there are 3 or more dots on a splitter, but when changing the orientation then there is only one dot.
sometimes there are lines, but when switching to disabled these lines are much bigger. But only in one orientation.

When you drop a RadSplitContainer in a RadDock ToolWindow, RadSplitContainer loses important options from its SmartTag's ActionMenu.
Similar behavior is obtained when you drag a RadSplitContainer from the ToolBox and drop it onto an empty RadDock.

Hello, I receive 'failed to create component' when designing user control in WinForms Designer.
RadControls version - Q3 2014
Visual Studio version - 2013 Community
Seems like there was a try to add a reference to already referenced assembly.
The image is in attachment

SplitPanel - there is no property Name in Visual Studio designer.

Let's have a RadSplitContainer on a form. This RadSplitContainer should contain two SplitPanels and one splitter. Change the color of the splitter using the Edit UI Elements dialog. Run the project and you will get IndexOutOfRangeException. However, if you cut and paste the designer code in the form_load, it will work correctly.

Applying Settings to the RadSplitContainer >> SplitContainerElement >> SplitterFill element affect only the first Splitter instance in the RadSplitContainer.