visual studio 2010

F# runtime for Silverlight version v4.0 is not installed.

After playing with some Silverlight beta bits, going back to RTM, etc. I could not compile F# projects for Silverlight 4 anymore. Even after reinstalling everything in [what I think is] the right sequence I was still getting this error:

F# runtime for Silverlight version v4.0 is not installed.
Please go to to download and install matching F# runtime
C:\Program Files (x86)\Microsoft F#\v4.0\Microsoft.FSharp.Targets

I followed the link and re-installed the Microsoft Silverlight 4 Tools for Visual Studio 2010 (which I already did), but the error was still there. Looking into c:\program files (x86)\Microsoft F#\Silverlight\Libraries\Client I noticed that the folder v3.0 was there, but not v4.0.

The solution

If you have the same issue, go to and download the Silverlight 4 Tools installer (Silverlight4_Tools.exe).
Don’t run it, instead extract its contents with your zip tool of choice (I used WinRar) and run FSharpRuntimeSL4.msi.
Now look again in c:\program files (x86)\Microsoft F#\Silverlight\Libraries\Client, a v4.0 folder should have appeared. If you have it your Silverlight 4 F# projects should now compile.

Team Foundation Server upgrade 2005->2010

Very smooth upgrade. Except:

  • Dell boot cd for our PowerEdge server does not support windows 2008
  • Dell does not support our RAID/SCSI controller for windows 2008 (no drivers)
  • Team Foundation Server does not run on windows 2003 R2 64-bit
  • Windows 2003 msdn DVD is not bootable. But there is an identical one (minor version +1) that is bootable.
  • SQL server 2008 R2 msdn DVD contains by mistake the evaluation version without key (thus starts in evaluation mode). Fortunately the SP1 DVD is correctly pre-pidded.
  • Thunderstorms caused three power failures (we have no UPS).

All in all it took 4 complete days, a hundred reboots and a lot of cookies. Not a funny experience. Maybe that’s why they pay sysadmins to do this kind of stuff.

However I must say that all the issues were not directly caused by TFS and the TFS 2010 setup itself is impressively smooth and straightforward. A huge step ahead compared to 2005, congrats to the TFS team!

Silverlight 4 is out…

…just a word of caution for developers: if you are still developing with Silverlight 3 and VS2008 don’t install the Silverlight 4 runtime. If you do, you won’t be able to build your SL3 application anymore and you’ll spend the next hour

a) looking for a way to make your app build again

b) looking for the SL3 runtime (that you won’t find anywhere –and won’t correct the situation anyway).

This problem should not arise if you are already on VS2010 because it allows you to choose your target between SL3 and SL4, but if you are stuck with VS2008 you are out of luck.
It seems that the folks at MS think that everybody can just go ahead and migrate all their solutions to VS2010 and SL4 the next day things are released.

Epic fail! Rant over.

P.S. the correct way to make things work again is:

– uninstall the Silverlight 4 runtime (listed as “Silverlight” in the Programs & Features panel)
– restart your machine (no, you cannot skip this step!!!)
– download the Silverlight3 Developer Runtime and install it (hurry up because as soon as they’ll notice they will remove it from the download server!)

And no, you won’t be able to view SL4 websites –but at least your app will build.

UPDATE: forget the rubbish above. If you install the Silverlight 4 developer runtime you will be able to run SL4 apps and build SL3 apps (of course if you had the SL3 SDK). Just don’t install the “normal” SL4 runtime.