In Visual Studio 2010, the dependent assembly of a custom control assembly will be deleted from the project’s Bin folder on project clean or rebuild if the project does not contain a reference to that dependent assembly. The result will be a WAP that successfully builds but fails at runtime. When adding a control from such a custom control assembly, both the custom control assembly and the dependent assembly will be added to the bin folder of the WAP. However, only the reference to the primary assembly will be added automatically to the references node of the project, but the reference to the dependent assembly will not. If the dependent assembly is not required at the compile time, then usually, users would not add it to the references node…(read more)