I have already downloaded this: AStudio6_2sp2_1548net.exe Is there any reason this would work better than Visual Studio Community 2013?

I pulled that off trying to resolve my other issue - but if it would work I'd put it back on.

Thanks - it said 'menu' so I went to the menu when the steps fell apart.  That link led me the right way it seems and  that got rid of the overwhelming number of errors and boiled down to a set of standard defines not found.

I am using the newest BETA Teensy loader and first release of Arduino 1.6 support, registered in Visual Studio as 'Arduino 1.5 +'

It seems some standard header is not being referenced in this code that worked as I saved it from the Arduino IDE -  Errors are Visual Studio 2013 "Intellisense: Identifiers:

pinMode, OUTPUT, Serial, LED_BUILTIN, delay, millis.

Three of which are on these two lines from an included Teensy example:
  pinMode(ledPin, OUTPUT);
  Serial.begin(38400);

Compiling 'T_HelloSerialMonitor' for 'Teensy 3.1'
:macro names must be identifiers
:ISO C99 requires whitespace after the macro name [enabled by default]
:"F_CPU" redefined [enabled by default]
:this is the location of the previous definition
Error compiling

I checked. Teensy does not support Arduino 1.6 yet.

You have to use 1.0.5 or 1.0.6

https://www.pjrc.com/teensy/td_download.html

Thanks

As of last week - when I powered up my Teensy 3.1 units full support for 1.6 is in wide beta with the newest version of "TeensyDuino 1.21-beta 6" and is the only thing I've used since unwrapping mine.  

https://forum.pjrc.com/threads/27740-Arduino-1-6-0-any-plans-to-support-it

Also by Mid-March folks will have a new Teensy-LC in their hands. Final Beta boards are out with March 10 the expected release date.  It goes along with the above software updates.  It is a <$12 version Teensy 3.1 layout with M0 instead of M4 class MCU and corresponding reduced specs.