System Information
Operating system: Linux-4.19.0-9-amd64-x86_64-with-debian-10.4 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 418.113

Blender Version
Broken: version: 2.83.5, branch: master, commit date: 2020-08-19 06:07, hash: rBc2b144df395f
Worked: Not sure, possibly 2.82a

Short description of error
When using sculpt mode, the Dyntopo menu will fail to display after using the Box Hide brush. The Dyntopo information cannot be seen either in the drop-down (top of screen) or in the Active Tool Menu (right side of screen). I only have officially supported / included addons enabled, e.g. LoopTools, F2, BoolTool, etc.

Exact steps for others to reproduce the error

1. Open the attached blend file (garbage4-begin-sculpt.blend)
   garbage4-begin-sculpt.blend8 MBDownload
2. Select the mesh for the character's head
3. Optional - in object mode apply scale with CTRL+A
4. Tab into Sculpt Mode
5. Click the Dyntopo drop-down. You will notice it works normally
6. Enable Dyntopo with the checkbox
7. Choose the Box Hide brush
8. Hide a section of the head mesh using the Box Hide brush
9. Click the Dyntopo drop-down. Notice it no longer works. (see attachments)
   
10. Click the Dyntopo settings in the Active Tool Menu and notice that they are empty even when expanded. (see attachments)

11. Look in your terminal, and you will notice that the Python traceback:

Traceback (most recent call last):
  File "/home/user/pathto/blender-2.83.5-linux64/2.83/scripts/startup/bl_ui/space_view3d_toolbar.py", line 822, in draw
    brush = settings.brush
AttributeError: 'NoneType' object has no attribute 'brush'

location: <unknown location>:-1

location: <unknown location>:-1