Could not create sencha application, even having the correct versions compatible with CMD and Framework

Question

Could not create sencha application, even having the correct versions compatible with CMD and Framework

There is no debugger in the whole code. Everything is fine on local.But, as soon as I started building the application, it shows the following error. In addition, everything works fine in the development folder. However, when I try to create an assembly, I get the following error.

[ERR] BUILD FAILED
    [ERR] com.sencha.exceptions.ExNotFound: Failed to find mixin class: mymixin.language
    [ERR]
    [ERR] Total time: 6 seconds
    [ERR] The following error occurred while executing this 
    line:C:\TestApp\apps\myapp_dev\.sencha\app\build-impl.xml:367: The following error occurred while executing this line:C:\TestApp\apps\myapp_dev\.sencha\app\js-impl.xml:11: com.sencha.exceptions.ExNotFound: Failed to find mixin class: boseui.language9:35:39 PM"C:/Users/myaccount/bin/Sencha/Cmd/4.0.4.84/sencha" app refresh