Operating system: Windows 7 x64
Graphics card: NVIDIA GeForce GTX 580
Broken: 2.80 e2102e991764
Placing a keyframe outside of the range of an NLA Strip while in Tweak Mode crashes Blender entirely. System console reports: "Attempt to free NULL pointer"
Exact steps for others to reproduce the error
Open attached .blend, enter Tweak Mode on the NLA strip, move to a frame outside the NLA strip's frame range, translate the Cube and insert a keyframe.