Hello
I would say si not supported and not expected to work, however you will need to try instructing the AUT to be launched in CLR v.4 runtime:
Mofify the app.exe.config file and add this
<configuration>
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0"/>
</startup>
</configuration>
Applications that do not allow this modification to app.config are not supported in LR11.50 and you will need to try version 11.0
for additional details check on http://msdn.microsoft.com/en-us/library/bbx34a2h.aspx
Hope this helps