Name <namespacename> in the root namespace <fullnamespacename> is not CLS-compliant
An assembly is marked as <CLSCompliant(True)>, but an element of the root namespace name begins with an underscore (_).
A programming element can contain one or more underscores, but to be compliant with the Language Independence and Language-Independent Components (CLS), it must not begin with an underscore. See Declared Element Names (Visual Basic).
When you apply the CLSCompliantAttribute to a programming element, you set the attribute's isCompliant parameter to either True or False to indicate compliance or noncompliance. There is no default for this parameter, and you must supply a value.
If you do not apply the CLSCompliantAttribute to an element, it is considered to be noncompliant.
By default, this message is a warning. For information on hiding warnings or treating warnings as errors, see Configuring Warnings in Visual Basic.
Error ID: BC40039
To correct this error
If you require CLS compliance, change the root namespace name so that none of its elements begins with an underscore.
If you require that the namespace name remain unchanged, then remove the CLSCompliantAttribute from the assembly or mark it as <CLSCompliant(False)>.