Error: Failed to compile fragment shader

When I use PlayCanvas version 2.7 and above (Engine only), I get this error:
Failed to compile fragment shader:
ERROR: 0:315: ‘texture_heightMap’ : undeclared identifier
ERROR: 0:315: ‘texture’ : no matching overloaded function found
ERROR: 0:315: ‘r’ : field selection requires structure, vector, or interface block on left hand side

This issue doesn’t occur in version 2.6.2 or earlier, which are the releases prior to 2.7. Do you have any insights? and how to fix?

You’re right, the shader still does not compile, I reopened the issue and will fix it.
Note that the offset mapping implementation is really old, and not useful these days anymore, we have this issue to replace it with a more modern implementation: Confirm our simple parallax mapping functions as expected · Issue #5209 · playcanvas/engine · GitHub