POSTPONED: I think this will be solved when we'll switch to binary shader serialization. For now, I guess avoid specifying too large/small numbers as default property values. Materials actually having these values are fine, just the defaults in shader text are not...

A shader that has very small or large floating-point number literals in its property block doesn’t work on the player.

Repro:
For example, a shader with the following property turns pink when built.

_Foo("Foo", Float) = 0.0000001
_Bar("Bar", Float) = 1000000

Note that it works on the editor. It seems to get broken when building player.