I booted with a USB then resized dev sda5 and got unallocted.
Then resized sda3 and got another unallocated outside of sda3
Then I rebooted to my Ubuntu and tried to mount unallocated, but nothing is selectable in menu.
I want to install windows in that 50 GiB area. For a dual boot selection.
Sometimes I have to use windows!
thanks for your help!