I had to reboot my Dev Machine on which I have my SQL Server 2012 Business Intelligence Setup. After reboot, It turns out that when I wanted to open the SharePoint Site (for Power View related work) – it gives me error:
HTTP Error 503. The Service is unavailable”
Turns out, for my scenario – the default application pool had stopped:
So this is what I did to solve the error:
1) Verified that the account and password for the App Pool is correct
2) Started it.
This is how you do it:
Start > IIS Manager > Application pools > Locate Default Application Pool that stopped > Verify that Account and Password are correct. > Start it.
After doing that, the SharePoint site started working again!