In my case the problem occured when i forgot to add the =0 on one function in my pure virtual class. It was fixed when the =0 was added. The same as for Frank above.
class ISettings
{
public:
virtual ~ISettings() {};
virtual void OKFunction() =0;
virtual void ProblemFunction(); // missing =0
};
class Settings : ISettings
{
virtual ~Settings() {};
void OKFunction();
void ProblemFunction();
};
void Settings::OKFunction()
{
//stuff
}
void Settings::ProblemFunction()
{
//stuff
}