And evrything crashed.... anyone knows what I did wrong?

[Grim]

Error: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Version: AGS 3.1.2.82

System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at GetRelativeSpriteWidth(Int32 )
   at AGS.Native.NativeMethods.GetRelativeSpriteWidth(Int32 spriteSlot)
   at AGS.Editor.NativeProxy.GetRelativeSpriteWidth(Int32 spriteSlot)
   at AGS.Editor.ViewPreview.previewPanel_Paint(Object sender, PaintEventArgs e)
   at System.Windows.Forms.Control.OnPaint(PaintEventArgs e)
   at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer, Boolean disposeEventArgs)
   at System.Windows.Forms.Control.WmPaint(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Now, what has just happened to my AGS?

[TerranRich]

Errors and crash reports should go in the main Technical Forum. CJ's really the only person who can tell you what went wrong, with a few exceptions perhaps.

[RickJ]

Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

.. or that you are attempting to use more memory than has not been allocated.   It seems like you are working with dynamic sprites and the drawing commands?  If so I would check to see if you are deleting  any dynamic sprites  you create when they are no longer needed.  I would expect that if dynamic sprtes are continually created,. eventually an error complaining about memory would be eventually encountered.

[Pumaman]

What had you just done when this happened? Had you just imported some new sprites?