Terrain Editor Turns Black, Won't Edit

In 2019.2 and 2019.3, when I try to use the Terrain tools to edit a piece of terrain, the scene blacks out and I can’t raise or lower the terrain. I have installed the Terrain Package from the Package Manager, and I have installed the Terrain Sample assets from the Asset Store. I am working on a Mac running High Sierra 10.13.6 with an AMD Radeon HD 6770M 512 MB GPU. I am a teacher running a lab full of these machines, and this happens on all of them. On my Windows laptop at home, I can edit the terrain. Any suggestions?

Video of issue

Just to update this, I managed to fix this problem on one machine, but most of the machines in the lab are still having this error. I have no idea why or how it works now on the other one. The console error is :

RenderTexture.Create failed: format unsupported for random writes - R16 SFloat (45).
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

I tried upgrading to the LWRP on one of the machines with the problem, but that did not help.

This is a very frustrating error to hit when 20 students are ready to build terrain.

Additionally, when I zip a file that works on one machine and send it to a machine that does not work, the file will not work on the new machine. This means (I guess) that the problem is linked to a setting in the machine or in the broader unity context, rather than a file specific setting.

Additionally, I had a student for whom this error DID NOT happen before he installed the terrain tools from the Package Manager, then after he installed the Terrain Package, he got the black screen no editing.

I have exact same problem, it’s a problem with the Terrain tools code, it’s hard coded to use “R16_SFloat” as the render texture format, but our Mac’s don’t support that format, so until the preview package is fixed to allow a different format / detect that it’s not usable and switch to another automatically, we won’t be able to use the tools on our mac’s.

try to remove package and then restart your projact, that has helped me