Can't open smartgit, Java error
Solution 1:
Don't use the PPA. Simply grab the software from the developer's website.
https://www.syntevo.com/smartgit/
I always use the "Download for Linux" version. Just unpack it, and you can run the .sh file directly. There is also a convenient add-menuitem.sh script in the /bin folder, that creates shortcuts for Smartgit, so you can start it from your desktop environment's launcher.
Just move the unpacked folder first to somewhere where you won't lose it. Like ~/Documents probably is a safe place.