What's 'ambiguous reference between 'x' and 'y'' error in c# about?

This error suggests that two referenced namespaces have types with the same name, causing ambiguity.

Example:

var ambiguousType = new AmbiguousClass();

Solution:

var specificType = new MyNamespace1.AmbiguousClass();

To resolve, specify the fully qualified name of the type to disambiguate.