Invalid properties in the .ofs file for the message class
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
The error "One or more properties in the .ofs file are not valid for the message class selected" appears when you import a form region that is designed in Outlook, but one or more fields on the form region aren't compatible with the message classes that you select on the final page of the New Form Region wizard.
For example, you might select Task (IPM.Task) on the final page of the New Form Region wizard. If the form region has a Business Address field, you'll receive this error because a task doesn't have a business address. Therefore, the Business Address field is not compatible with the IPM.Task message class.
You might select Task (IPM.Task) on the final page of the New Form Region wizard. If the form region has a Business Address field, you'll receive this error because a task doesn't have a business address. Therefore, the Business Address field is not compatible with the IPM.Task message class.
To correct this error
On the final page of the New Form Region wizard, select a message class that is compatible with the fields on the form region.
In the Forms Designer in Outlook, remove fields that aren't compatible with the message classes. Remove fields that you plan to select on the final page of the New Form Region wizard.