Forcing .NET framework 3.5 in Microsoft Visual C# 2012 -

because of compatibility reasons, need compile project under .net 3.5. microsoft visual c# 2012 not offer option.

i'm getting compiler error:

the type 'system.action' defined in assembly not referenced. must add reference assembly 'system.core, version=3.5.0.0

for code:

powertrader.powerstartedcallback = delegate {     emergencymode(false); }; powertrader.powerstoppedcallback = delegate {     emergencymode(true); };

this available selection in ide:
enter image description here

what should do?

portable class libraries .net 4+ only. not support .net 3.5.

you have create normal class library project instead.

And