Silverlight projects became "unavailable"?

YukunXing

A while back I was going through the ESRI SL 4 tutorial and set up a few projects using MS Visual Web Developer 2010 Express, thing were working fine. Haven't touched them in months and tried to work on a project today and got a pop-up message, saying "You need to install the lastest Silverlight Developer runtime befor opening Silverlight project 'project name'" with a link.

If I ignore it and proceed, the .Web portion of the project will load, but not the other one, which was marked as "unavailable" in the solution explorer.

If I try to download the "latest Silverlight Developer runtime" following the link, it won't install, saying "a 64 bit version is already installed". In addition, I noticed it was trying to install SL5, which I probably don't want since everything up to this point was done in 4 in my case.

I haven't altered anything on my system. The only suspect I can think of is that I installed the latest MySQL (binary installer for Windows) yesterday. Could that be the culprit?

Any help is appreciated.

Yukun

YukunXing

Did you ever find a solution to this?  I am having the same issue.  I'm trying to upgrade from the ArcGIS API 2.4 and Silverlight 4 to API 3.0 and Silverlight 5.   I get this message when I try to create a new application.

I'm not a full time developer and only play with it on the side when I have time. I checked the projects and it seems this particular issue is gone. However, since it's been so long I couldn't remember what I did - checked a few places and emails, didn't see any clue. Sorry that I couldn't be more helpful.