When trying to build in Unity I’m getting the error: shader error in ‘standard’ too many math instructions for sm2.0 (65 needed, max is 64). Try #pragma target 3.0 at /Program Files/Unity/Editor/Data/CGIncludes/UnityStandardCore.cginc(424) (on d3d9).
I don’t use any custom shaders in my project, so this seems a bit strange. I’ve already tried restarting unity and my computer. Then I thought updating unity might help, I was using 5.6.1, and downloaded the new version, 2017.1.0, but to no avail. Something to note is that this error does not happen 100% of the time, and it seems like it happens most when I first open unity. I can use the play button in the editor and it seems to run fine. I also tried deleting my library and letting unity create a new one.
Furthermore, when building, I had task manager open and I took this screenshot of the cpu usage.
It seems strange that the shader compilers would take up this much cpu when I’m simply using the default shaders. I have an i7 6700 for reference.
I also looked at the file that the error message pointed to and here are the relevant lines:
423 half4 c = UNITY_BRDF_PBS (s.diffColor, s.specColor, s.oneMinusReflectivity, s.smoothness, s.normalWorld, -s.eyeVec, gi.light, gi.indirect); 424 c.rgb += Emission(i.tex.xy);
So maybe it has to do with emission somehow? I only have one material with emission and it appears fine when the build does work or if I run from the editor.
Thanks in advance for any help!

I found a solution this morning (I think it's working, didn't test it yet). According to this tweet (https://twitter.com/John_O_Really/status/1026941844444405760), it seems like you need to use the "Sample Texture 2D LOD" node tomake it work with positions !
– Tsequier