Biztalk/VS Error Message "non-readonly field property access is limited to distinguished fields on class-based messages"

Do you run into the following error while building your Biztalk project?

Non-readonly field property access is limited to distinguished fields on class-based messages.

Visual Studio seems to misinterpret your property access to the XmlDocument message, for example with MSG.DocumentElement.LocalName. It assumes that you want to access a distinguished field, which is not allowed here.

Mahesh explained this error on MSDN - it comes from the installation of Hotfix 2851429 in CU2. According to Microsoft, it will be fixed with CU3; if you do not want to wait, you should contact Microsoft Support.

Until then, the only solution that helped me was to un-install the CU2.

Here the screenshot of the error:

UPDATE on July 8th, 2014: The issue is solved in BizTalk 2013 R2.