Rocks'n'Diamonds

If you'll test your level while properties of custom element is open, you'll have all standard toolbox buttons instead of special CE buttons (copy to, copy from, swap, copy and paste). Then click on Draw single items button, you'll get visual replacement of three top buttons with CE buttons, but only visual, they will be then replaced with originals on click of each (draw connected, draw line and draw arc)

Can confirm that this still happens in the current version except the CE toolbox buttons only appear after clicking on one of toolbox buttons once, which also triggers the properties screen to close. Clicking again resets the CE buttons.

That was a nasty one (took me several hours to find out what's going on).

Fixed now!