Hi Mac Inger !
They have stopped developing shake for PC, the last version is 2.5.
so either u can go for Shake V4 for Linus, and make ur PC run of Linux.
Why its not opening in shake 2.5 is, almost most of the nodes have been upgraded and modified only very few nodes of shakeV4 opens in ShakeV2.5, so its better to go for Shake4.
( if u want to know where its going wrong, u open ur shake flow in a text editor and select (highlight) first 25 lines and drag it in to ur shake and continue this for the next consecutive 25 lines, then u will know wehre all its stuck)
thanks and good luck