Visual Studio 2010 Error The Product key cannot be used to extend the use of this product

After a gap of few weeks, today when I fired up Visual Studio 2010 Professional on my lappie, it showed me a dialog box, to obtain a new license key to extend the trial version.

As usual, I tried obtaining a new license online and pasted this key in the activation window and hit Activate button, but no luck, it keeps on throwing this error:


"The product key cannot be used to extend the use of this product"

Searched on the internet and came to this msdn forum http://social.msdn.microsoft.com/Forums/en-HK/vssetup/thread/518bc51d-56e1-4224-89d0-0645808d6b78 which eventually took me to this link, which proved very useful to troubleshoot the above error.

http://www.mydigitallife.info/master-product-key-to-upgrade-activate-visual-studio-2010-ultimate-premium-and-professional/


Tip:  You can directly use the master key mentioned in the above link, it starts with YCFHQ..., just google it and you are good to go ;-)

Update - Tip - Visual Studio 2010 Ultimate and Dynamics AX .Net Business Connector Compatibility Settings

Issue:

I bumped into this error when building my .Net app (using Visual Studio 2010 Ultimate)  which consumes Dynamics AX 2009 (.Net Business Connector assembly)

 Solution -

Update - In my specific scenario, I'm not leveraging any of the .Net 4.0 Framework features, so I just changed the Framework Version to 3.5 to make this work.

But, if you are targetting .Net 4.0, you need to perform an additional change in config after you change the Framework version to 4.0 otherwise you will run into the following error:

"Mixed mode assembly is built against version 'v2.0.50727' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information"

In order to fix this error, just add this specific entry in your app.config under configuration section:

startup useLegacyV2RuntimeActivationPolicy="true", so now your modified app.config should look like the below:

And you should be good to go now with .Net 4.0!

P.S Florian has a theory on .Net 4.x compatibility with AX 2009 BC in his blog , but without making this additional change in config as I have shown above, it won't work and as said before I was just using a basic .Net 3.5 targetted app just to test one of my AX BC Classes