VS 2015 use the .Net 4.5 Debugger as default. If you have another .Net Framework version in your project you have to create a "Winword.exe.config" file in the same directory as Winword.exe.
This is an Winword.exe.config example content for targeting .Net framework version 2.
<configuration>
<startup>
<supportedRuntime version="v2.0.50727"/>
</startup>
</configuration>
(This is not a NetOffice specific behavior)
*Sebastian
This is an Winword.exe.config example content for targeting .Net framework version 2.
<configuration>
<startup>
<supportedRuntime version="v2.0.50727"/>
</startup>
</configuration>
(This is not a NetOffice specific behavior)
*Sebastian