Option 1: Go to Setup → Reset Settings . ( Goes to Default settings)
Option 2 :
please check following.
Go to → \AppData\Local\UiPath → Open layout.xml.
there you can see the below line.
if IsOpen it’s false. Please make a true and save the file , before that close all the UIpath studio window.
( am using RPA platform trial version) you may try on above steps on your end.