Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 465.89
Broken: version: 2.93.0, branch: master, commit date: 2021-06-02 11:21, hash: rB84da05a8b806
Short description of error
Blender crashes when selecting off an object in Object mode to an object that's in Sculpt mode when Lock Object Modes is disabled, but only after saving and reloading file first (and any subsequent attempts after). Things I've tried: disabling all plugins, 2.93.0 (stable) and 3.0.0 (alpha), using different shapes (UV Sphere, Cube), using a different system (Asus ROG Zephyrus G14 laptop); but all have same issue at the moment.
Exact steps for others to reproduce the error
Exact same steps as https://developer.blender.org/T72147
Duplicate default cube, or create two objects of choice.
Turn off Lock Object Modes in Edit menu
For one of the cubes switch to the Sculpt mode
Select the object that's in Object mode
This will give you file:
Open Blender and open the .blend file
Try to select the second cube (the one in Sculpt mode)
Let me know if you need further info, appreciate your work Blender devs!