Operating system: macOS-10.14.6-x86_64-i386-64bit 64 Bits
Graphics card: Intel(R) Iris(TM) Plus Graphics 655 Intel Inc. 4.1 INTEL-12.10.12
Broken: version: 2.93.0, branch: master, commit date: 2021-06-02 11:21, hash: rB84da05a8b806
Worked: (newest version of Blender that worked as expected)
**Short description of error*
Normally (2.92) the left ball in the material preview viewport (bottom right) shows the HDRI but in the 2.93LT version it's just black. Perhaps there's an additional step I need to take to bring the HDRI back but I can't see how. I only noticed when trying to add a glass shader and getting no light response from the cube. I've attached screenshots comparing 2.92 and 2.93 on the same system.
Exact steps for others to reproduce the error
Change to Cycles engine. Enter material preview in shading tab. Delete Principle shader and add Glass shader.