>Electron is the source of electric field and changing electric field produce magnetic force...

The electron is the source of an electric field and the electron is the source of a magnetic dipole moment. Both are for a free electron intrinsic (existing independent from sourrounding influences) properties.

Our observations shows that a particle with two monopolar properties - an electric charge and a magnetic charge not exist. The search of magnetic monopoles is possible only on high energy physics and scales below the subatomic particles. The use of such an investigations should be a deeper understanding of the electrons inner structure and the structure of electric and magnetic fields and of photons.

>Why can't a particle that carries magnetic charge exist?

Electric fields are the reason for accelerations towards or away from other electric charges. Magnetic fields are the reason for deflection of charges. What should be the reaction of a magnetic monopole to the influence of another magnetic monopol? The same as for electric charges? How then we would differ between them? Why not agree that charges contain a monopolar field and a dipole field?