Rename namespace JetBrains.CodeDup.Lib so that it no longer conflicts with the reserved language keyword 'Lib'. Using a reserved keyword as the name of a namespace makes it harder for consumers in other languages to use the namespace. Consider merging the types defined in 'JetBrains.CodeDup.Lib.Cost' with another namespace. Rename namespace JetBrains.CodeDup.Lib.Cost so that it no longer conflicts with the reserved language keyword 'Lib'. Using a reserved keyword as the name of a namespace makes it harder for consumers in other languages to use the namespace. Per target sample Sign 'JetBrains.CodeDup.Lib.dll' with a strong name key. Per type sample Correct the casing of 'COST' in member name 'CodeDupSettings.DEFAULT_DISCARD_COST' by changing it to 'Cost'. Make 'Set<T>' sealed (a breaking change if this class has previously shipped), implement the method non-explicitly, or implement a new method that exposes the functionality of 'ICollection.SyncRoot.get()' and is visible to derived classes. Assemblies should have valid strong names Either the assembly has no strong name, an invalid one, or the strong name is valid only because of the computer configuration. The assembly should not be deployed in this state. The most common causes of this are: 1) The assembly's contents were modified after it was signed. 2) The signing process failed. 3) The assembly was delay-signed. 4) A registry key existed that allowed the check to pass (where it would not have otherwise). Sign {0} with a strong name key. http://msdn2.microsoft.com/ms182127(VS.90).aspx [none] CriticalError