"Paamayim Nekudotayim" means "double colon" in Hebrew; thus this error refers to the inappropriate use of the double colon operator (
::). The error is typically caused by an attempt to call a static method that is, in fact, not static.
If the above code causes this error, you most likely need to simply change the way you call the method:
The latter example assumes that
$classname is an instance of a class, and the
doMethod() is not a static method of that class.