Resolution:
Add at least one parameter to the extension method, which is required because it is treated as a pseudo-instance variable when the method is called.
Example:
In the following example, The M2 extension method has no parameter but is invoked such that a parameter is required.
class-id a static. method-id M1 extension. end method. method-id M2 extension (s as string) end method. method-id main static. declare s as string invoke s::M2 *> First parameter of M2 treated as pseudo-instance variable end method. end class.