I have some problems regarding the Intellisense in VS2015. The following functions and symbols are not recognized:
ISR,cli,sei,TIMSK0,PINB,...
digitalRead,pinMode,byte,HIGH,LOW,...

I do get a number of related errors during compile:
cannot open source file "WProgram.h"
identifier "digitalRead" is undefined
identifier "HIGH" is undefined
...

However, upload and code is working fine on the board.

I can solve most of the missing symbols by including 
#include "Arduino.h"
#include "avr/iom328p.h"

where the last line is problematic:
Attempt to include more than one <avr\ioXXX.h> file.

I am using the following:
Microsoft Visual Studio Community 2015 Version 14.0.24720.00 Update 1
Visual Micro 1512.20.2
Arduino 1.6.7
Arduino Uno R3

I have tried to:
1) reinstall the plugin
2) restart software and computer
3) switch to other board and back again
4) toggle the "Always Re-Add Header" intellisense option

Thank you in advance.

I installed the update but it did not fix the issue right away for my project in progress. However, by creating a new empty project and copying all code from the old one, the issue was gone. Now everything is working like a charm!

Thank you very much!

Best,
Ulrik