Setup fails because of custom action invocation - wix

Question

This is the situation:
When I compile in Debug mode (VS2013), in temporary folder I see LOG file that created with following error:
FXCA: Extracting custom action to temporary directory: C:\Windows\Installer\MSIF661.tmp-\
SFXCA: Binding to CLR version v4.0.30319
Calling custom action GlobalCustomActions!GlobalCustomActions.CustomActions.CheckInputParameters
Exception thrown by custom action:
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.TypeInitializationException: The type initializer for 'GlobalCustomActions.CustomActions' threw an exception. ---> System.ArgumentException: An item with the same key has already been added.
at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
at GlobalCustomActions.CustomActions..cctor()
--- End of inner exception stack trace ---
at GlobalCustomActions.CustomActions.CheckInputParameters(Session session)
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object parameters, Object arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object parameters, CultureInfo culture)
at Microsoft.Deployment.WindowsInstaller.CustomActionProxy.InvokeCustomAction(Int32 sessionHandle, String entryPoint, IntPtr remotingDelegatePtr)
CustomAction caCheckInputParameters returned actual error code 1603 (note this may not be 100% accurate if translation happened inside sandbox)
Action ended 15:56:17: caCheckInputParameters. Return value 3.
Action ended 15:56:17: INSTALL. Return value 3.
Action ended 15:56:17: ExecuteAction. Return value 3.
Action ended 15:56:17: INSTALL. Return value 3.
If I compile in Release, the same code runs good and custom action executes just fine.
And another input: this code was compiled before in Debug mode and worked fine.
I ensured that useLegacyV2RuntimeActivationPolicy set to true and both frameworks are supported.