To reproduce:
1. Create a new project with Universal RP template;
2. Upgrade Universal RP package to 7.1.1 (latest SRP master);
3. Observe the error in the console

OR

1. Create new project
2. Import Core RP Library, Shader Graph, and Universal
3. Set Graphics API to Vulkan
4. Create a new PBR Shader Graph
5. Open the new Shader Graph

Result: "ArgumentException: Attempting to create a zero length compute buffer
Parameter name: count" is thrown

Reproduced with Unity 2019.3.0a12 and when upgrading from 7.0.1 to 7.1.1 package.

Notes:
1. The error is thrown always when upgrading SRP packages, and sometimes when opening the project.
2. The error is not thrown if I open a new template, close the project, change manifest file to 7.1.1 and open the project again
3. Tested and reproduced on OSX Mac Editor, Win Vulkan Editor

Fixed in Universal RP 7.1.2