Linux Mint 17.3 Cinnamon 64-bit Spacer applet doesn't work properly.

[Adam]

 Mint 17.3 Cinnamon 64-bit There is not possible to use more then one spacer applet on taskbar and what's more after delete them all and then add it once again, there are always more and more spacers listed in spacer's settings on and on and on. It's not possible to remove it from list

[Adam (adczerski)]

even reboot doesn't help and after adding another single spacer to taskbar number of listed spacers still increases

[CliffFish (cmeekins71)]

Mint 17.3 Cinnamon 64-bit - exact same situation. Delete all instances of Spacer app, remove Spacer app from panel, reboot, add Spacer app to panel, new instance becomes the n+1 instance of the previously removed instances which have all reappeared.
Multiple occurrences of the Spacer app cannot be manipulated. Adding more than one instance "stacks" the spacers on "top" of each other, and when an attempt is made to move the spacer(s) in panel edit mode, the spacer stack with all instances will be moved to the new location but attempting to add another instance adds the spacer to the relocated "stack".