Symptoms

Microsoft updates were recently installed (KB3122660, KB3127231, and KB3098785) on the server. After that, it’s not able to open any existing K2 workflow projects in Visual Studio. We get the following error: "The application which this project type is based on was not found. Please try this link for further information".
In the K2 compatibility documentation, it says that 4.6.xx supports .NET version 4.6. Does this also include minor versions, e.g. .NET 4.6.1/.NET 4.6.x? This is unclear from the documentation, see error message below.

  <entry>

    <record>530</record>

    <time>2016/02/17 00:12:25.784</time>

    <type>Error</type>

    <source>VisualStudio</source>

    <description>End package load rPackage_name]</description>

    <guid>{xxxx.xxx.xxxx.xxx}</guid>

    <hr>80131509</hr>

    <errorinfo>The tools version "4.6" is unrecognized. Available tools versions are "2.0", "3.5", "4.0".</errorinfo>

  </entry>

Diagnoses

This issue was reproducible and a bug was logged for investigation to be fixed in a future update.
 

Resolution

A fix is available for this issue. Please log a K2 support ticket to request the fix.