GLSL compilation failed: `vs_TEXCOORD3' undeclared, cannot construct `vec4' from a non-numeric data type

On import / reimport into fresh project on Ubuntu 20.04 with any build target and any render pipeline setting, four shaders fail to compile:

- Regular Polygon Additive

- Regular Polygon Multiplicative

- Regular Polygon Opaque

- Regular Polygon Transparent

All errors are line-number variants of:

GLSL compilation failed:
0:72(25): error: `vs_TEXCOORD3' undeclared
0:72(20): error: cannot construct `vec4' from a non-numeric data type