If you are upgrading from R93 you can use shortlink.php from the zip (there are no other changes)
I'm sorry for this bug but I was rushed by the shortlinkers to release R93.
There is another tiny bug in R94 - you can't set 0 (zero) reward for solving the shortlink. It will be fixed in the next version. Until then you can use 0% to get zero reward.
Please beep me if you get any issues with this version .