Repair/Modify operation did not finish successfully.

“Setup error – repair/modify operation did not finish successfully.” message shown when starting Visual Studio 2015

Problem: 

When starting Visual Studio 2015, the following message is shown

“Setup error – repair/modify operation did not finish successfully.”

Resolution:

This message is shown when a repair was previously performed on the Visual Studio 2015 software but it was not able to successfully complete. 

To resolve this issue amend the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\14.0\Setup\VS\professional

 IsInstallInProgress key should be set to 0