Greetings. As the title says, using Inverse Kinematics in the animation editor crashes roblox studio frequently.
I believe that crashes happen when attempting to move a part to an unsolvable position. Both rotation and moving can trigger this.
To replicate this bug, enable IK in the animation editor on a standard R15 block rig. Select the LowerRightArm or LowerLeftArm part and rotate it any amount of degrees in the opposite way an elbow normally bends.