I don\'t know how, but my STS has got duplicate toolbars items and I am not sure how to remove them. Here is how my duplicated toolbar looks like.
I want to
It looks like you have installed the Darkest Dark Theme plug-in. Try to uninstall it.
This closed source plug-in does load-time weaving to patch Java bytecode of the Eclipse platform (for legal reasons, to not have to publish their changes). In contrast of using a public API, load-time weaving patches have to be adapted for each (new) Eclipse version: an error in the plug-in can cause strange behavior of the Eclipse platform.
See also: Keyboard shortcuts in Eclipse Oxygen stopped working