Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.12
Broken: version: 2.82 (sub 1), branch: master, commit date: 2019-11-09 19:12, hash: rBb720c0f6aa68
Short description of error
Open Blender and go to edit mode add a 2 or more shape keys and try to add a drive to one Shape key, then you cannot add the target as a new Shape key
Exact steps for others to reproduce the error
1.Open Blender and add 2 ore mvoe shape keys
2.Add a drive to a shape key.
3.You cannot add a controller of the driver to any Shape keys.