Argument type is not CLS-compliant, why?

Question

I get the warning like this If you know what it is, please exp

Answer 1

Some more info:

• Writing CLS-Compliant Code

And you can get those warnings in a CLS-compliant assembly, that references a non-CLS-compliant assembly (and exposes its non-CLS-compliant members):

• Can an assembly that includes a non-CLS-compliant reference be CLS-compliant?