LightSwitch in dev11 beta fails launching application

Question

Hi,

whatever I try, when trying to launch a lightswitch app (even a simple dummy one), it fails before showing any controls on the screen by saying: "Could not load type 'System.Lazy from assembly 'mscorlib, Version=5.0.5.0, Culture=neutral, PublicKeytoken=..."

Best regards,

Christof

Answer 1

Hi Christof,

Another user reported a similar issue here where he had the Beta version of the Silverlight SDK installed: http://social.msdn.microsoft.com/Forums/en-US/LightSwitchDev11Beta/thread/bf98dd09-50c9-4351-9075-d01718d34f03

Does that solve your issue?

Regards,

---

Steve Hoag Microsoft aka the Lights Witch (IEnumerable of Newt)

Answer 2

Hi Steve,

thanks for the suggestion - having checked: I didn't have the beta version of silverlight SDK installed.  I see the SDK for silverlight 4 and the SDK for silverlight 5 on Windows 8 Consumer Preview.  (Assume they both came with VS 11.) 

Just to make sure, I unstinalled SL 5 SDK and re-installed, without luck though.

Any pointers are very much appreciated.

Best regards,

Christof

Answer 3

Microsoft Connect answered this when I reported the same problem: https://connect.microsoft.com/VisualStudio/feedback/details/731315/lightswitch-fails-in-visual-studio-11

This issue is a known issue is unfortunately related to a specific install order.

We made a fix to resolve this issue in the new LightSwitch/Dev11 setup installer but that only fixes this issue if you install LightSwitch/Dev10 first and then LightSwitch/Dev11 since the Dev11 installer runs last (and last one wins).

You'll still run into this issue if you install LightSwitch/Dev11 first and then LightSwitch/Dev10. Unfortunately we cannot change the Dev10 installer now that it's shipped. A way to workaround this issue is to run repair in the setup for LightSwitch/Dev11 from your Control Panel|Add Remove Programs.

Thanks for submitting the bug report.

- The LightSwitch Team