This isn’t an error in and of itself, but more of a feature of your debugger. Some properties require code to be executed so that the property can be read, but if this requires cross-thread interaction, then other threads may have to run as well. The debugger doesn’t do this automatically, but certainly can, with your permission. Just click the little evaluate icon and it will run your code and evaluate the property.
Just click the little evaluate icon at the right and it will run your code and evaluate the property.